Nowitzki, who entered the game 20 points shy of the historic milestone, hit 30,000 on a baseline jumper over Larry Nance Jr. with 10 minutes, 58 seconds remaining in the second quarter.
After Nowitzki hit a 3-pointer a little more than a minute later, his Mavs teammates and owner Mark Cuban mobbed him during a timeout while the American Airlines Center crowd gave him a roaring standing ovation. He waved to the crowd, his emotions peaking when he noticed longtime mentor Holger Geschwindner tearing up, before a tribute video played on the arena's big screens.
"Dirk! Dirk! Dirk! Dirk!" the crowd chanted before play resumed.
"It's been sort of surreal -- 30,000 is amazing, a lot of points," Nowitzki said after finishing with 25 points and 11 rebounds in the Mavs' 122-111 victory. "Obviously, every milestone makes you reflect a little bit, reflect on people who helped you, been with you all this way, from all the coaches and Cuban and all the teammates I had, the fans that went with me through thick and thin.
"It's been an amazing ride, and hopefully a couple of more baskets are coming and then it's time to ride off into the sunset."
There are now six 30,000-point scorers in NBA history, with Nowitzki joining Kareem Abdul-Jabbar, Karl Malone, Kobe Bryant, Michael Jordan and Wilt Chamberlain. Malone, Bryant and Nowitzki, who plans to play at least one more season, are the only players to score at least 30,000 points for one team.
"Congratulations to Dirk Nowitzki on joining the NBA's most exclusive 30,000-point club," NBA commissioner Adam Silver said in a statement Tuesday night. "Throughout his 19 seasons with the Mavericks, Dirk has been a model player and terrific ambassador for our game. This latest accomplishment further establishes his legacy as one of the NBA's greatest players."
Former teammate Steve Nash, who, like Nowitzki, was acquired by the Mavericks in a trade on draft night in 1998, offered his congratulations via Instagram.
Big congrats to my buddy Dirk! 30 stacks!!! Only six players in the history of the game have scored 30,000 points. On this day in '98 I would've never believed you'd still be with the @Mavs, be an MVP, NBA Champ and in the 30k club no matter how many nights we went back to the gym for 1 on 1 and shooting battles. Unreal, historic, clutch player and better person.
LeBron James took time away from dinner with his family to send his thoughts via Uninterrupted.
Nowitzki opened with a scoring flurry that was spectacular even by the standards of his prime. He scored on the Mavs' first two possessions, hitting a midrange jumper and a 3-pointer from the top of the arc, and added another 3; a pump-fake, one-dribble, and-1 jumper; and a turnaround off a post-up before taking his normal rest in the middle of the quarter. He had 14 points on 5-of-5 shooting at that point, matching the Lakers' total.
After checking back into the game a few minutes later, Nowitzki immediately got another bucket, knocking down a pick-and-pop jumper. He finally missed on his seventh field goal attempt.
Nowitzki had a chance to get 30,000 on the first possession of the second quarter, but he air-balled a baseline jumper.
"Leading up to it, every basket I felt the buzz in the crowd," Nowitzki said. "Coming out the second quarter, sitting on 18 and the first play was called, I remember walking out and everybody already got up, so I got a little nervous and hoisted an air ball."
It was a minor hiccup during a vintage performance, with Nowitzki hitting the milestone less than a minute later from essentially the same spot on the floor.
"For me, this was a 13-minutes-and-2-seconds microcosm of one of the greatest careers in the history of this game," Dallas coach Rick Carlisle said. "Meticulous preparation, total commitment, unbelievable competitive spirit and real flare for the moment."
Nowitzki recalled thinking, "Why not?" just before launching the 3 on the second possession of the game. He figured he might as well find out if he could get hot on a potentially historic night.
"Go for it, let it ride," Nowitzki said. "A lot of play calls came my way early. Guys kept finding me in good spots, and I just said, 'You've got to let it ride. Go for it.' And I was able to get hot really, really early. That helped to get it out of the way. You don't want to drag this on. Guys tried to feed me. It was perfect that way. We were able to get it out of the way and play a good team game after that."
Nowitzki's 18-point first quarter matched the highest-scoring opening frame of his career. It also was the highest-scoring quarter by a Dallas player this season. He had 25 points by halftime for the first time since Nov. 16, 2008.
Nowitzki finished one point shy of his season high after going scoreless in the second half.
"The guys stopped passing to me," Nowitzki joked. "I got hot, and then they want to go for theirs. Nah, it was kind of surreal for me. I didn't really have that same edge afterward. I was just kind of glad it was over. But great win."
The victory, the Mavs' 16th in their past 25 games, pulled Dallas within two spots of the Denver Nuggets for the Western Conference's final playoff spot. Asked about celebrating his accomplishment, it didn't take long for Nowitzki to mention that the Mavs have an important back-to-back against the Brooklyn Nets and Phoenix Suns to wrap up their homestand this weekend.
But Nowitzki, whose longevity is due in part to his commitment to a strict diet and exercise routine, did enjoy the moment in a way that would make his original Mavs coach, Don Nelson, proud.
"I just had a Bud Light for the first time in a long time," Nowitzki said.