The 2018 Valero Texas Open took an unexpected twist on Saturday in Round 3 as Trey Mullinax shot a TPC San Antonio course-record 62 and now sits one back of co-leaders Zach Johnson (-13) and Andrew Landry (-13) heading into Sunday. The former Alabama star Mullinax is surrounded by plenty of tour vets, but he put on an absolute show in Round 3 (more on that below).

This event has been decided by a single stroke in three of the last four years, and with eight golfers within four strokes of the lead, this year is likely to be much of the same. 

With a good board loaded up after 54 holes, here are four takeaways from Saturday's play in San Antonio.

1. The Trey Mullinax experience: Never heard of him? Get used to the name. Mullinax is a potential future star. He leads the PGA Tour in driving distance on the season (not a typo), and on Saturday he led the field in San Antonio with a tournament (and course) record 62. It's the best round of the entire week by an astounding three shots, and Mullinax did it with a 29 (!) on the back with a bogey (!). He eagled two of the last five and finished 3-4-2-3-3 (two of those were par 5s). All in all, it was an all-time round from him.

He said he told his caddie on No. 18, "I think that might be the course record." His caddie responded, "if it's not you still played pretty good."

Mullinax actually shot a 74 on Thursday and faced the cut on Friday. He birdied each of the first three holes that day and hasn't looked back. Of the last 36 holes he's played, Mullinax has birdied or eagled 14 of them. Now he'll go for win No. 1 in just his 41st start on the PGA Tour.

2. Zach Johnson's career: If co-leader Johnson wins on Sunday, he will join Adam Scott, David Duval and David Toms at No. 72 on the all-time wins list with 13 PGA Tour victories. As a quick aside: If I put Adam Scott and Zach Johnson in front of you and made you watch both of their swings, which one would you think had more PGA Tour wins?

Anyway, Johnson is the +150 favorite, and he should be. He's been terrific over the last two days and sits in the top 10 on the leaderboard in both strokes gained around the green and strokes gained putting. Mullinax is certainly the sexier pick, but he's a little out of his world being ranked No. 1 in the field in strokes gained putting. The regression there is easy to see coming, but Johnson is just doing what he's best at (laying up and scoring).

3. Remember Andrew Landry? The eventual 2016 U.S. Open sacrificial lamb en route to Dustin Johnson's first major has popped up here and there since that first great showing. His most notable result was a playoff loss to Jon Rahm at the CareerBuilder Challenge earlier this season, but he's quietly putting together a really strong year with three top 10s so far and another one seemingly on tap this week. 

Landry played splendidly coming home on Saturday with birdies on two of his last three, and a Sunday heads-up match between him and Johnson is going to be paradoxical. Johnson has crushed around and on the greens, and Landry has gained nearly 10 strokes on the field on approach shots and drives. He also doesn't have a bogey in his last 35 holes.

4. Joaquinn Niemann scared the top: At 7 under and six back of the lead, Niemann probably doesn't have a chance to win, but bring me all of his stock. The Chilean is coming off a missed cut at the Masters and playing in just his fourth PGA Tour event ever, and he shot a 67 in Round 3 to slide on into the top 10 after 54 holes. He's a former No. 1 amateur in the world, and the pedigree could not be stronger. I can't wait to see what he does on Sunday.