They say that a playoff series doesn't truly begin until a road team wins a game. Well if that's the case, then the second-round series between the Boston Celtics and Milwaukee Bucks is underway. 

Coming out with an impressive defensive game plan, the No. 4 Celtics frustrated the top-ranked Bucks all afternoon long, before pulling away in the fourth quarter for a 112-90 victory to take a 1-0 series lead. 

Al Horford was tremendous, finishing with 20 points, 11 rebounds, three assists and three blocks, while also shutting down potential MVP Giannis Antetokounmpo on the defensive end. The Greek Freak couldn't get anything going, as his drives to the basket were shut off on a consistent basis. He finished with 22 points, but needed 21 shots to get them. 

Meanwhile, Kyrie Irving finished with 26 points, 10 assists and six rebounds in another stellar postseason performance. The Celtics also got strong games off the bench from Gordon Hayward and Terry Rozier, who combined for 22 points, 12 rebounds and eight assists. 

The surprising blowout win for the Celtics sets up a vital Game 2 on Tuesday night. Already down 1-0, the Bucks cannot afford another loss to open up this series. 

Here are some takeaways from a stunning Game 1:

Horford steps up

Al Horford is somehow still underrated after all these years, but he stepped up once again on Sunday afternoon with a huge performance. Not only did he finish with 20 points, 11 rebounds, three assists and three blocks, but he played fantastic defense against Giannis Antetokounmpo. The Greek Freak couldn't get going in Game 1, and it was due in large part to Horford. The veteran is one of the few players in the league with the combination of strength and athleticism to make life difficult for Giannis, and he certainly did so in the opening game. Though Giannis got 22 points, he needed 21 shots in order to get them. 

Celtics' defensive game plan stifles bucks

The Celtics were one of the best defensive teams in the regular season, and they proved as much in Game 1. It all started with the way they were able to contain Giannis. Horford led the way in that regard, but the entire team was committed to collapsing down into the paint in an effort to shut off his drives and frustrate him. It worked, as Giannis never really got going in Game 1. He made just seven shots, and three of them were 3-pointers, which the Celtics are happy to live with. 

Giannis' shot chart from Game 1

And in exchange, they were willing to give up some open 3s to the Bucks' role players and force them to hit shots. They didn't, with Brook Lopez, Sterling Brown, Ersan Ilyasova, Eric Bledsoe, Pat Connaughton and George Hill combining to shoot 4-of-26 from downtown. Though the Bucks were one of the league's best 3-point attacks in the regular season, they did so more through volume than having elite shooters. That came back to bite them in Game 1, as they went cold. 

Irving and Hayward prove their worth

The Celtics beat the Bucks in the first round last season, but needed seven games to do so with their shorthanded roster. This time around, Kyrie Irving and Gordon Hayward are healthy, and though it didn't pay dividends in the way they hoped in the regular season, it has so far in the playoffs. Both were strong in their sweep against the Pacers in the first round, and both had strong games in Game 1 on Sunday. 

Irving, in particular was special, hitting a number of incredible shots in the first quarter to help the Celtics get out to an early lead. He finished with 26 points, seven rebounds and 11 assists, and made the right decision between shooting or passing on a consistent basis. Hayward, meanwhile, came off the bench for 13 points, four rebounds and five assists. His ability to not only score, but facilitate is vital to keeping the Celtics' offense afloat when Irving is out of the game. He may not be 100 percent back to his All-Star form, but it's clear that Hayward is feeling confident in himself, and that's a huge boost for the Celtics. 

Revisit all the news, highlights and updates from Game 1:

No. 1 Milwaukee Bucks vs. No. 4 Boston Celtics

How to watch Game 2

  • Date: Tuesday, Apr. 30
  • Time: 8 p.m.
  • Location: Fiserv Forum -- Milwaukee, Wisconsin
  • TV channel: TNT
  • Live stats: GameTracker
  • Online streaming: fuboTV (try it for free)
  • Odds: N/A at this time

TV listings

All games will air on ESPN, ABC, TNT and NBA TV during the postseason. Games on TNT and NBA TV can be streamed via fuboTV (try it for free).

Odds and Analysis

Check Sportsline's NBA pick sheet for all your daily odds.