In a season marred by upheaval, can Celtics turn it around after beating Raptors?

It’s too easy to laud the Celtics for their impressive win over the Toronto Raptors Wednesday night, especially as they pulled away because of late-game execution, something that has not been as prevalent as expected this season.

The key to the Celtics’ season is what happens now, now that they’ve proven they can beat elite teams and now that they have 38 games to make up a six-game deficit on the Raptors in the Eastern Conference.

The Celtics have a stretch of 14 games before the All-Star break, 10 at home, where they can make up significant ground, continue to gain chemistry and cohesion with their healthy roster, and better define roles as they enter the stretch run.

This is a critical period for this team. The first 44 games have included upheaval, team meetings, revelations, and some infighting. And yet, the Celtics have an opportunity to win the East and fulfill their potential.

There are reasons for optimism: Aron Baynes is back and played a sizable role in the win over Toronto. The Celtics’ defense is dramatically better with Baynes on the floor, as evidenced by Toronto’s reluctance to attack the basket with his large presence in the middle.

In Baynes’s absence, the Celtics have been crushed on dribble penetration. There was no better example than New Year’s Eve in San Antonio, when the Spurs repeatedly drove to the basket against Al Horford or Daniel Theis and either scored at the rim or dished it out to an open 3-point shooter.

On Wednesday, Raptors guards drove into the paint, saw the bearded Baynes, likely offering a bright, inviting smile, and then drove back out. Baynes was a plus-7 in his 14 minutes and expect to see a lot more of him once he gets back into basketball shape.

That may mean less playing time for Theis, who did not play Wednesday. It’s been a rocky season for Theis, whose defensive rating has risen to 106 this season after being 100 in his rookie year.

“Well, Baynes has been doing non-contact workouts for two weeks now, and shooting the ball, running, you know, wearing out all our machines in the facility,” Celtics coach Brad Stevens said. “So, like he’s — you knew he was going to be in great shape; that wasn’t going to be an issue. And I thought he really battled down there and the three he hit was huge. I mean, that was a big momentum, because it was going the other way at that time and he just stepped up and knocked it in.”

Another reason for optimism is the play of Gordon Hayward, who is warming to being the main offensive weapon in the second unit. The splits show that Hayward is flourishing off the bench. In 24 games as a reserve, Hayward is averaging 11.6 points on 45.2 percent shooting and 35.5 percent from the 3-point line, compared with 10.2, 38.4, and 28.6 in 16 games as a starter.

Some of those numbers can be attributed to Hayward working himself into shape after missing all of last season, but Hayward is also becoming more comfortable with his role and his ability to get the shots he wants as the offensive leader of the reserves.

“We have to play hard like that, with energy, every single night,” Hayward said. “I think when we do that, we move the ball, we move bodies, get easier looks, there’s some more flow, some more rhythm, it’s good for all of us.”

And the Celtics were able to reach the 30-assist mark for the 16th time this season. They are 12-4 when they collect at least 30 assists, with three of those losses coming in November. So the Celtics are a better offensive team when the ball moves and the wealth is shared.

Kyrie Irving recorded a career-high 18 assists against Toronto. He is averaging a career-best 6.7 assists per game and shooting 40 percent from the 3-point as well as a career-best 54.2 percent on 2-point shots. The Celtics are a better team when Irving is more of a distributor and less ball dominant. On Wednesday he was both, scoring in key stretches when the club needed a bucket but clinching the game with a pair of assists to Horford at the basket and finally feeding Jayson Tatum for the punctuating fast-break dunk in the final 30 seconds.

“Being able to make some shots, and sticking together, no matter what the score was or where the game was heading,” Irving said. “I felt like it was our game, you know, for the majority of the game. They came out and hit us first and we had to respond.

“I thought we did a great job of that, but it also helps when you have Baynes out there, defensive presence, offensive rebounds, getting you extra opportunities, and then everybody fills in around the energy we’re putting forth. It felt good to get this win against a great team like the Raptors and kind of make a statement for ourselves that we’re obviously capable of playing against the best and beating the best and just try to build on our consistency going forward.”

That’s the key, building on this victory moving forward. Friday’s game against Memphis and Saturday’s matchup at Atlanta are just as important as Wednesday’s win. The question is whether the Celtics will react accordingly with the same sense of urgency.

Gary Washburn can be reached at gwashburn@globe.com. Follow him on Twitter @GwashburnGlobe.