The crowd in the locker room was sparse when the Thunder came to Boston last season. An inexperienced Oklahoma City team had just fallen to 20-53, and even though they had an exciting young player in Kevin Durant, there wasn’t much to say about the club other than that they had the potential to win … sometime in the future.

That time has arrived. On Wednesday, that same team put on a show and stole the spotlight at TD Garden. Led by 37 points from Durant, the Thunder beat the Celtics 109-104 (click here for the full recap) and improved to 46-28, just one win shy of Boston’s 47-27 record.

The matchup between the Celtics and Thunder transformed from a mismatch of experience to a neck-and-neck battle of two legitimate playoff contenders. Despite shooting nearly 60 percent from the field, the Celtics were outnumbered at the free throw line. They shot 13-for-17 as a team, while Durant shot 15-for-15 himself — which drew a strong postgame response from Kevin Garnett

“I thought we were playing Michael [expletive] Jordan tonight the way he was getting the whistle,” Garnett said after the game. “Durant damn near shot more free throws than our whole team.”

A year ago — or even just four months ago when the Celtics beat the Thunder, 105-87, on the road — it was hard to imagine a game between these two teams would stir up such a reaction. But just as the Hawks established themselves as a young threat on the Celtics homecourt, the Thunder did the same.

And it goes without saying that the locker room was much more crowded after Wednesday’s game.

Here are three things we learned from this offense-driven game.

SHEED STEPS UP

To say that Rasheed Wallace played one of his best games of the season would be an understatement.

There was the play where he hit the ground fighting for a rebound, the moment when he made one of his most aggressive dunks of the season, the instant in which he drained a clutch 3-pointer, and the time when he set a pick on Durant so tough that it allowed Rajon Rondo to find Garnett for an open jumper.

He paired a nearly flawless 18-point performance (7-for-8 from the field) with hustle and energy that sparked the C's second unit.

Wallace, who has opted for long-range jumpers at many points throughout the season, attacked the paint and got to the basket. It was a style he chalked up to simply being part of the game.

“Just playing,” he said. “I guess it was the play-calling and just running through the plays, just cycling through the plays.”

Even if he considers it “just playing,” Boston coach Doc Rivers was pleased with his shot selection. 

“I thought he was on the post a little bit more. He just played well,” Rivers said. “It’s a human game. You can struggle a whole year and you keep working and it may turn for you. That’s why I don’t stay in the past very long. The guy is working and practicing every day. You just hope he keeps working and keeps improving.”

Wallace gave his all on a night when Kendrick Perkins (knee) estimated he was only at 75 percent. He picked up just three fouls in 26 minutes — his lowest in four games — and kept himself on the court while Perkins rested on the sidelines.

PAINTING IT GREEN

Attacking the paint is a fundamental part of basketball, but an area where the Celtics aren’t always consistent.

“I think that defensively they kept us out of the paint,” Ray Allen said after the Celtics were beaten by the Spurs Sunday. “It forces a perimeter, we didn’t get anything in transitions.”

The C’s took note from that loss and attacked the paint early — and often — on Wednesday. Twenty of their 23 first-quarter points came in the paint; the three that didn’t were free throws. The entire team bought into the game plan, too. Seven of the eight Celtics who played in the first quarter got on the board, yet no one scored more than four points.

The C’s had a 36-20 edge in the paint at halftime and pushed that to 56-40 by the end of the game. They surpassed their season average of 43.6 points, scoring 16 more points in the paint than they did in their previous loss to San Antonio.

Getting to the basket was one of the reasons why the Celtics shot an impressive 59.5 percent from the field. It is also one of the reasons why the loss was disappointing. Even though the C’s took care of business in the paint, they could not stop the Thunder (28-for-34 FT) once they got to the line.

“It’s got to be tough, when you look at it, shooting so good and it not paying dividends in the win column,” Paul Pierce said. “It’s tough to swallow, and then you look at the free throw discrepancy, so you have to look at that and say that’s where we gave up points and that’s where we lost the game.” 

A MATCHUP FOR THE FUTURE

Going into the game, Rajon Rondo believed the matchup between he and Russell Westbrook would be one to watch for the next six or seven years. After their performances on Wednesday, it is easy to see why.

“They both are very athletic point guards. They’ve both improved every year they’ve been in the league,” Oklahoma City coach Scott Brooks said. “Rondo is one of the best point guards in basketball and he does so many things well that he controls the game. It’s great to have a point guard like Russell and Rondo. Defensively, they’re tough and they want to get better. They want to lead their teams.”

Durant may have stolen the show, but the duel between the two young point guards was captivating for four quarters. Westbrook posted 21 points and 10 assists while Rondo scored 16 points and 11 dimes. Rondo also picked off five steals along the way.

“It was fun to watch,” Durant said. “Those are two great point guards. I think Russell should have been an All-Star this year, but Rondo’s been playing very well since he got into the league and led them to a championship. But it was fun to watch. They went at it all game.”

With his 11 assists, Rondo is just one away from tying the Celtics franchise record of 715 career assists set by Bob Cousy in 1960.

“It’s phenomenal,” Wallace said. “To be in that same class … Bob Cousy was a hell of a player. He was a trendsetter from the things he used to be able to do on the court with his whole playing style and his passing style; for Rondo to be this early into his career and break a record like that, that’s pretty good. That’s saying something about the potential that he has.”