After five years of debating who is the best welterweight boxer in the world, Errol Spence Jr. and Terence Crawford are excited to finally leave the talking behind as they set to take action in Saturday's first four-belt undisputed title fight in 147-pound history

But for as sick as both fighters are of being asked about each other, which was evident in Thursday's saucy final press conference in Las Vegas, the pair of unbeaten champions have vowed they will produce the kind of fight inside T-Mobile Arena this weekend (Showtime PPV, 8 p.m. ET) that will have people talking for many years to come. 

In the biggest fight in boxing since Floyd Mayweather and Manny Pacquiao squared off in 2015 following their own five-year soap opera build, Spence (28-0, 22 KOs) and Crawford (39-0, 30 KOs) bring old-school mentalities into a fight that has left those who experienced firsthand prior welterweight unification classics like Ray Leonard-Thomas Hearns (1981) and Felix Trinidad-Oscar De La Hoya (1999) expecting a return feeling of that nostalgic, big-fight feel. 

Even better, both fighters have promised to go through one another in order to get their hand raised, which has left even boxing's cynical crossover audience, the same who still aren't over paying $100 on pay-per-view for Mayweather-Pacquiao only to receive a defensive and technical superfight, expecting nothing but fireworks. 

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"This is going to be legendary. Make sure you tune-in. This is gonna be an old school fight," Spence said on Thursday. "It's gonna be iconic. You're going to want to buy this fight. You're getting your money's worth.

"People are going to talk about this fight 30 or 40 years from now when you talk about legendary fights. They're going to talk about this fight the same way they talked about the 'Four Kings' era. There's going to be an amateur 20 years from now watching our fight on YouTube and saying 'man, I want to be in a fight like that.'"

The 35-year-old Crawford, who puts his WBO title at stake against the trio of welterweight belts owned by Spence, largely echoed his opponent's prediction of a spectacular fight. The difference is Crawford, who has won titles in three divisions and has a chance on Saturday to become boxing's first male two-division undisputed champion of the four-belt era, expects it to turn into a one-sided affair. 

CBS Sports will also have live coverage of the fight with round-by-round scoring and blow-by-blow updates to keep you up to date throughout the night.

"[Spence] is going to find out the same thing that everyone else finds out. He's going to say that on TV I look one way. In the ring he's going be seeing three of me," Crawford said. "They say he's the big bad wolf, but come fight night we're gonna find out if he's all that he says he is. He's going to have to show me.

"This is the Terence Crawford era. When you look at my body of work in each weight class, you can't deny that. This is my era. I've never had a close fight. I've never had a fight where people thought I lost. I've looked spectacular every time."

Spence, 33, has the deeper resume of the two as a welterweight, where has has campaigned for all of his 10-year career. The 2012 U.S. Olympian has made six defenses of the welterweight title he first captured by stopping Kell Brook in 2017 and has scored resounding victories over the likes of Yordenis Ugas, Shawn Porter, Danny Garcia, Lamont Peterson and Mikey Garcia. 

The only difference this time, for both fighters, is that each will be facing the most talented, accomplished and determined opponent of their respective careers.

"I don't think there's anyone I fought who is similar to Terence Crawford," Spence said. "His style is different from anybody else. I don't think 'Sugar' Ray Leonard fought anyone like Tommy Hearns until he fought Tommy, and vice versa. That's what happens in these historic fights."

The good news for boxing fans, who have already enjoyed a 2023 that is on pace to be the sport's best calendar year in two decades, Saturday's fight could just be the beginning as each champion has agreed to a bi-lateral rematch clause that can be activated by either one, regardless of the result (although the winner gets to choose the contracted weight of the rematch). 

"This fight is happening at the right time. All the belts are on the line, so there's even more to fight for," Crawford said. "This solidifies everything. This is the fight that boxing needs. With the magnitude and the stage and just everything that's surrounding this fight, yes I needed Errol. But legacy-wise, I had already accomplished a lot and was already a Hall of Famer. This win is the cherry on top for me."

While the hostility is still there, including between the two families and fanbases as both have continued to chirp all week long at one another, both men remained cordial at the weigh-ins. After Spence and Crawford hit the mark of 147 pounds, they shook hands for the final faceoff. While they still threw out a couple of final thoughts to the other, there was no pushing or shoving as they know it will all be settled in the ring come Saturday night.

"Everyone knows it's 'Strap Season'. I want to thank my parents, because they blessed me with the resiliency to get through a lot of stuff in life," Spence said. "Make sure you order the fight on Showtime PPV. I guarantee you I'm gonna put on a great show. Bring your seasoning on Saturday night, because we're gonna have a crawfish boil. Bring that hot sauce too.

"I guarantee you it's gonna be nothing but fireworks from start to finish."

While the main event deservedly has all the attention this week, fans will be treated to a solid undercard in the buildup. Look no further than the co-main event where Isaac Cruz returns to take on Giovanni Cabrera in a WBA lightweight title eliminator. Cruz has been pushing all week to get his rematch with Gervonta "Tank" Davis after he gave Davis one of the toughest tests of his career in December 2021. Plus, veteran Nonito Donaire looks to make another run at a title when he takes on Alexandro Santiago for the vacant WBC bantamweight crown. And opening the PPV is an intriguing junior middleweight tilt between Sergio Garcia and Yoenis Tellez.

Let's take a look at how the top two fighters in the 147-pound division match up. 

Tale of the tape

FighterErrol Spence Jr.Terence Crawford
Nickname The Truth Bud
Hometown Desoto, Texas Omaha, Nebraska
Age 33 35
Record 28-0, 22 KOs 39-0, 30 KOs
Titles IBF, WBA, WBC welterweight WBO welterweight
Height 5-foot-9 1/2 5-foot-8
Reach 72 inches 74 inches
Stance Southpaw Orthodox
Best wins Kell Brook (KO11, 2017), Shawn Porter (SD12, 2019), Yordenis Ugas (TKO10, 2022) Yuriokis Gamboa (TKO9, 2014), Viktor Postol (UD12, 2019), Shawn Porter (TKO10, 2021)

What's at stake?

Like Mayweather-Pacquiao in 2015, this fight will be contested between the best two fighters of the division and their respective era while also having the potential for the winner to stand alone as the best pound-for-pound fighter in the sport at this moment. 

The difference for Spence-Crawford is that all four recognized titles in this undisputed clash are at stake for the first time in the division's history (boxing's four-belt era began in 1988). This is the 13th welterweight unification overall and just the fourth time in division history that a pair of undefeated defending champions will face off. 

While it's true that both Spence and Crawford have already cemented spots in the International Boxing Hall of Fame and are both looked at as all-time greats who are still at the peak of their respective games, both need a clean victory to separate themselves historically from one another in ways that Mayweather-Pacquiao, due to the global stardom both had already accrued and the dominant success of each in the lower weight divisions, didn't. 

Who has the edge?

1. Power: Both fighters can crack with both hands and each possesses a nasty side to their game as surgical finishers once they have their opponent's hurt. But Spence is among the biggest and most physically brutal welterweight champions in history. He's a more dangerous inside fighter than Crawford and appears to hold an edge from the standpoint of being able to change the course of a fight with one single punch. Advantage: Spence

2. Speed: There isn't a strategy or style that each champion can't employ or adapt to. But if there's something separating each of them, it's the fact that Crawford is slightly slicker. A big part of that is his foot and hand speed, which fuels his all-around game. Advantage: Crawford

3. Defense: From a statistical standpoint, they compare well with each other. But it goes without saying that because Spence employs a much more physical and stalking style, he opens himself up more to being hit. While his defense largely remains responsible, even within heavy fire, Crawford is the more elusive of the two. Advantage: Crawford

4. Technique: This one is closer than recent memory might suggest. For as bruising as Spence has been of late, including breaking Ugas' eye socket in their 2022 unification fight, he once outboxed the highly skilled Mikey Garcia with ease from distance over 12 rounds just to prove a point. With that said, few in history can match and smooth flow of Crawford, who switches stances with ease and somehow becomes more dangerous (and creative) once he commits each fight to going southpaw. Spence had the more successful amateur career but Crawford hits you with punches you don't see coming and can often flow in and out of danger without getting touched. Advantage: Crawford

5. Intangibles: It would be foolish to question the heart, determination and ability to rise to the occasion of both fighters. Just watch tape of their biggest wins over the last decade. But coaching matters and Spence has boxing's reigning trainer of the year in Derrick James behind him. Spence also has a more proven chin of the two and a one-way mentality set upon breaking Crawford that is hard to deal with when one considers his imposing size and incredible gas tank. Advantage: Spence

Who wins Errol Spence Jr. vs. Terence Crawford, and which prop is a must-back? Visit SportsLine now to see Peter Kahn's best bets for Saturday, all from the boxing specialist who has netted his followers a profit of nearly $4,000, and find out.