SALT LAKE CITY -- Deron Williams used to get a boost in Utah when Jazz fans roared in approval every time he did something good on the court.

On Monday, Williams thrived under a chorus of steady boos from his old faithful.

Williams scored 23 points, Dirk Nowitzki dropped in 22 and the Dallas Mavericks clinched at least the seventh spot in the Western Conference playoffs with a 101-92 win over the Utah Jazz on Monday.

"This game meant a lot to us," Williams said. "We knew it meant a lot to them as well, so coming in here we knew this was going to be like a playoff atmosphere. Essentially, it was a playoff game because there was so much at stake."

One team, the experienced Mavericks, looked like a grizzled old playoff club.

The other, the extremely young Jazz, looked like they were lost for much of the night.

"I think some days are diamonds and some days are stones. Tonight was no doubt a stone," Jazz forward Gordon Hayward said. "Tough way to lose for us."

The Jazz's playoff hopes suffered a huge hit with the loss.

Utah and Houston, which routed the Timberwolves in Minnesota, are now tied with 40-41 records. The Rockets own the tiebreaker over the Jazz and host Sacramento, which won't have DeMarcus Cousins or Rajon Rondo, on Wednesday.

Utah travels to Los Angeles to take on the Lakers in Kobe Bryant's career finale that same night.

Houston can clinch a playoff spot with a win, while the Jazz need to beat the Lakers and have the Rockets lose.

Dallas is in for good and could end up with the sixth seed.

"Well, it's been a lot of work. It's been an amazing two weeks," said Dallas coach Rick Carlisle, whose team has won seven of eight to make the playoffs. "Our guys looked like they were down and out, and we all dug in. Everyone dug in, especially the players and we found a way to get into the playoffs."

Hayward scored 26 points with six rebounds and four assists for Utah, but he was 1-for-9 from 3-point range. Shelvin Mack scored 18 points and Derrick Favors contributed 11 points after starting the game on the bench because of a knee injury.

The Jazz finished hitting just 9 of 33 3-pointers.

“Just a night where we don’t hit shots, and that starts with me. That’s contagious. Got to be better,” Hayward said. “We couldn’t ask for better looks for a lot of us on the team. I think we executed what we wanted to offensively and got the right looks. We just didn’t knock them down. I have to be better and this one’s on me for sure.”

This game became a painful reminder of the Jazz's season story when starting center Rudy Gobert, the anchor of Utah's defense, twisted his ankle in the second quarter. Gobert, who was leading the Jazz with six rebounds in 12 minutes, hobbled to the training room and didn't come out with the team after halftime.

Dallas, which controlled the game throughout, came out strong after halftime, taking a 66-54 lead after a Williams 3-pointer.

Utah showed some life after that, going on a 10-0 run. Utah had a chance to go ahead, but Hayward missed a deep shot.

The Mavs responded with five straight points to end the quarter and continued their 7-0 run into the fourth quarter for a 73-64 lead.

While Utah's offense continued to flounder, the Mavs stretched their lead back to double digits at 77-66. Utah pulled within five in the final two minutes, but Dallas fended off the late rally.

Wesley Matthews added 18 points for the Mavericks, who improved to 42-39 with a clutch win at Vivint Smart Home Arena.

In the first half, Williams looked like the All-Star who used to play for the Jazz. He scored 18 points on 8-of-12 shooting to lift Dallas to a 50-46 lead at the break.

Williams added six assists and four rebounds against his former team, while Nowitzki grabbed 11 rebounds.

Williams admitted the boos fired him up.

"I'd be lying if I said it didn't. It got me going out there a little bit," he said. "Not only the booing, but the stuff that was being said when I was sitting on the bench, at dead balls, stuff like that."

NOTES: Jazz coach Quin Snyder believes his team, which he noted has the least amount of experience in the NBA, will take a valuable lesson out of this playoff push whether the team makes it or not. "When you think about those two things together, being involved in a situation like this for us is -- obviously you want to win -- but it's a no-lose situation in that sense." ... Mavs coach Rick Carlisle has been impressed by the Jazz's power forwards, Derrick Favors and Trey Lyles. "They are both a problem," he said. "Lyles is coming off a career-high (Sunday, 24 points); Favors has been a big challenge for us the last three years." ... The Mavericks have four players on their roster who played for Utah earlier in their careers: PG Deron Williams, PG Devin Harris, SG Wesley Matthews and PF Jeremy Evans.