It was just the second time in his playoff career he played the entire fourth quarter and failed to score, the last time being that infamous eight-point game in 2011.
But then the second half happened and the Cavaliers wilted.
The series resumes Tuesday night at Quicken Loans Arena before returning to Boston on Thursday for a Game 5 that didn't appear necessary until the Celtics stormed back from 21 down and won when Avery Bradley's 3-pointer danced an Irish jig on the rim before falling with 0.01 seconds left. He turned out to be right.
Believe it or not the pressure will be amped up on the Cavs to win should the Golden State Warriors complete their sweep of the San Antonio Spurs on Monday night.
The Cavaliers quickly built their lead up to 20 points in the first two minutes of the third quarter before getting a bit sloppy. "Our goal is to win every game we play".
So with that as the backdrop, knowing full well that no one outside of their locker room gave them an ice cube in hell's chance at winning Game 3, the victory brought about a level of satisfaction that Celtics players had seldom experienced before if at all.
Battling a hip injury the past two months and then playing through the darkest period of his life, he proved an inspiration while dedicating his performances to his late sister. Vegas made the Cavs 17-point favorites.
Smart had a monster frame for the Celtics, contributing 11 points, nine of which from beyond the arc.
San Antonio has been outscored by 73 points since Leonard left Game 1 with 7:52 remaining and the Spurs leading 78-55.
"Everybody had to step up their game tonight especially with one of our brothers down", Smart said. "We were getting good shots on offense and playing with great objective, and on defense I thought we were much better than the score indicated".
As Vegas Insider shows, the point spread for tonight's National Basketball Association game opened at 5-1/2 points but moved all the way to 17 points in favor of the Cleveland Cavaliers based on the news of Thomas being out for the rest of the playoffs.
This would be higher on the list if not for the disastrous three games that followed. Love hit zero 3s in the second half. Johnson would return to action in the second quarter. Several times the Cavs would drive into the paint, only to jump and contort their bodies into awkward positions to try and pass out to the 3-point-line.
The lack of rhythm and lack of an attacking mindset was evident exclusively in LeBron James' night, if not elsewhere.
"Well, one of the things, as you go back and watch the film, I thought LeBron made a lot of the right plays", Stevens said. Conversely, the Celtics buried five of their 11 three-point tries in the fourth quarter. He looked passive and lethargic, like he wasn't interested in anything other than moving on to Game 4.