With less than two minutes to play in the third quarter Saturday night in Dallas, Russell Westbrook bolded and underlined what was perhaps his signature performance in his one short season wearing a Washington Wizards uniform. The only blemish on his night was that it came in a hard-fought, 125-124 loss to the Dallas Mavericks.

With his team up three, Westbrook charged Jalen Brunson from behind for a steal just as Brunson caught the pass and then sprinted downcourt for a statement slam that he capped with a roar and a world-class snarl. It wasn’t the finishing flourish on another triple-double — Westbrook fell one assist short of that — nor was it the bucket that matched his season-high 42 points, which came in the fourth quarter.

But the steal, the dunk, the stare-down after — it was classic Westbrook, a neat personification of the gut-busting performance that got Washington out of an 18-point deficit and gave it a chance against Luka Doncic’s Mavericks in the first place.

In the end, though, it was erased when Doncic found Dorian Finney-Smith in the corner for a three-pointer with 9.3 seconds to play to give Dallas what turned out to be the game-winning basket.

On the next possession, Bradley Beal had the ball at the top of the key but lost his dribble, only for guard Raul Neto to pick it up and serve it right back to Beal behind the three-point line. His attempt missed, and Dallas held on.

“We made a mistake,” Wizards Coach Scott Brooks said of the Mavericks’ final possession. “We’re up two; we talked about it after the game — we’ve got to learn from it. Rui [Hachimura] made a mistake. He switched the pick and roll up top, [and] Russell had him inside the three. ... Rui’s a terrific player. But we can’t give up a wide-open three or a late-contest three. We’ve got to know the score and do a better job. But like I said, he didn’t do it on purpose. ... We haven’t been in those positions a lot, and we haven’t practiced a lot. We haven’t practiced at all, those situations, in three months. It’s a tough break. We have to learn from it, but we’ll be in this position again.”

Brooks later said Washington had “nothing to be ashamed of” for the way it came back against the playoff-bound Mavericks (36-27).

But on a night when the Wizards (29-35) took a small stumble in the race for play-in positioning, widening the gap between their No. 10 spot and the Indiana Pacers’ No. 9 to 1½ games, Beal had a more acerbic takeaway. It didn’t help that Indiana creamed Oklahoma City, 152-95, on Saturday.

“Shouldn’t have lost the game. Should not have lost the game,” Beal said. “We’re down 18, played really good to come back, played really well the last couple minutes down the stretch and just had some mishaps. I even had a little mishap, getting Luka the wide-open pull-up [jumper] before the Dorian Finney-Smith three. Just have to lock in, be better.”

Beal had the ball in the final seconds, but Westbrook shouldered the burden of making the Wizards competitive in the second half.

He finished with 42 points, 10 rebounds and nine assists. Beal, no slacker, added 29 points, 10 of which came at the foul line. Hachimura had 18 points, and center Daniel Gafford had nine points, seven rebounds and two big blocks, including one on Willie Cauley-Stein with the score tied at 111 and less than five minutes to play. Gafford streamed in from the opposite side for a huge left-handed swat, the type of play that exemplified Washington’s brash performance as the night wore on.

But Dallas was a tough customer. Doncic turned in a herculean 31 points, 20 assists and 12 rebounds, and Finney-Smith added 22 points that included six threes. The Mavericks shot 54 percent from the field that included 44.7 percent from three, a large part of how they built an 18-point lead early in the second quarter.

The Wizards climbed out of the hole with pure grit.

Westbrook got them to the front door, and the Wizards relied on gutsy role players, as well as Hachimura, to push it open. Washington tied the score three times late in the third quarter, first with a strong layup by Ish Smith after he collected a rebound of a Hachimura missed three and then again with a driving layup from Hachimura.

Two possessions later, Neto burst to the rim after a hesitation move to tie things again before Robin Lopez dunked and drew a foul to give the Wizards a three-point lead with 3:22 to play in the quarter — their biggest of the night to that point.

But down the stretch, defense was an issue for Washington as the teams traded leads and the Wizards seemed unable to come up with a stop.

Defense was the issue early on as well. Doncic, despite heavy-looking tape on his left elbow, which he cradled more than once after a hard fall early in the game, made himself the main character in a dominant first quarter before Westbrook countered with 18 points in the second to get the Wizards within five at halftime.

“I was just picking my spots — that’s about it,” Westbrook said during a short news conference after his big night. “Taking my time, attacking and trying to attack downhill.”

The point guard was just as direct when asked about his main takeaway from the close loss: “Just move to the next one.”

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