NBA playoffs: James Harden has...

Boston James Harden, a player with the Philadelphia 76ers and a former NBA MVP, is said to have gone to Las Vegas in between playoff games, dressed as Cookie Monster for Game 1 of the Eastern Conference Semifinals, and played against the Boston Celtics far more seriously than either action suggested.

The 33-year-old Harden's very efficient 45 points in a 119-115 victory at TD Garden on Monday may have been a turn-back-the-clock moment for the three-time scoring champion had there been many in our recollection of his postseason career. In the absence of injured Sixers co-star and MVP favorite Joel Embiid.

An all-time great who had previously faltered in several instances like to this played his trademark game in this contest.

Before the first game of the series, six-time All-Star Blake Griffin and fellow Celtics reserve Luke Kornet had a philosophical discussion in the Boston locker room about the nature of careers, how simple it is for athletes to lose themselves in negativity when most fall short of their championship goals year after year, and how steep the road down from the mountaintop can feel. Griffin was selected No. 1 overall in 2009, two spots ahead of Harden.

Neither could have predicted that Harden, who has received more criticism than his superstar colleagues, would team up with LeBron James and Stephen Curry to remind the NBA that they are still capable of winning the championship. Nobody anticipated it. In the first round, Harden struggled with his foot and was unable to defeat the Brooklyn Nets off the dribble.

The best that Harden could provide for the majority of the first half was a fadeaway midrange jumper or a step-back 3-pointer in the face of waves of Celtics who were even bigger and more athletic than Marcus Smart, Derrick White, Malcolm Brogdon, and them. He made a ton of them (7 of 10), accounting for 17 of his 21 first-half points. However, expecting him to carry the Sixers for four quarters on the strength of the hardest shots in basketball felt like asking too much of a player who missed the All-Star team for the first time in more than ten years.

Defenses used to accept anything Harden would provide them during his heyday. Not this at all. He had to struggle for every opportunity, and on 17 of the 30 shots he could make, including 7 of his 14 3-point tries, he converted. He only attempted four free throws, far fewer than the ten tries per game he averaged from 2012 to 2016.

Harden tied his postseason career best of 45 points from Game 4 of the 2015 Western Conference Finals. In that series, his Rockets were down 3-0 to the Golden State Warriors, a sign of a playoff resume marked by highs in low-pressure situations and lows in high-pressure ones. This was not that, either. With Embiid out indefinitely, the Celtics needed this home game to start the series, and Harden snatched it.

With 8.4 seconds left, Harden hit the go-ahead three-pointer, and an inaccurate Smart pass on the ensuing possession brought Boston's comedy of errors to a close. The Celtics made 59% of their shots, added six extra free throws, yet they still lost because they gave up 32 points in turnovers and second chances.

If Embiid's strained right knee cannot be healed and Harden performs worse on a day's rest than he did on nine (even if at least one of them was spent in Sin City), it is unknown whether the math can favor Philadelphia over a seven-game series. The only thing that counts right now is having a 1-0 series lead.