The 34-year-old moved to Texas last summer after 13 years with the Golden State Warriors.

The move was seen as a signal that the four-time NBA Championship winner was beyond his best.

But Thompson underlined his enduring quality with 22 points, seven rebounds and three steals in just 26 minutes.

Eighteen of Thompson’s 22 points came from three-point shots, which is a record for a player on their debut for the Mavericks.

“Great debut,” Thompson said.

“It’s only one game in October, but it feels good just to get that first one out of the way.

“I had a ton of excitement, really just an awesome feeling. And you only get the first time of something so often.”

The game was the first time that Thompson has played competitively with Mavericks superstar Luka Doncic, who said he was “rusty” after missing large parts of pre-season.

Doncic said of Thompson: “It’s easy to play with a guy like that. It makes your life easier. You got to find him.”

Elsewhere, the Boston Celtics made it two wins from two with a 122-102 victory against the Washington Wizards.

The Minnesota Timberwolves narrowly beat the Sacramento Kings 117-115, while the Denver Nuggets lost 102-87 to the Oklahoma City Thunder.

Thompson, 34, had not been left out of the starting line-up since he was a rookie with Golden State in 2012 – a run of 727 regular-season starts.

He also became the 153rd player in NBA history to reach 15,000 career points.

“Klay coming off the bench gives us a lot of firepower,” coach Steve Kerr said.

“We’ll give it a little look and see where it goes from there.

“He handled everything beautifully. The way he came out, determined and competitive, that’s not easy, to come off the bench for the first time in [more than] 11 years. It’s difficult.

“But Klay is a champion. He’s one of the most competitive people I’ve ever met. He responded accordingly and played a great game.”

Introduced seven minutes into the first quarter, Thompson scored 17 points in 12 minutes to give Golden State an 84-71 lead at half-time.

He is the sixth player in Warriors franchise history to reach the milestone of 15,000 points, joining Stephen Curry, Wilt Chamberlain, Rick Barry, Paul Arizin and Chris Mullin.

“Throughout the game, when I’m running with the second unit, I realised I might be more of a focal point to the offense,” Thompson said.

“That’s a fun role to play. I just wanted to take it upon myself to prove to coach [Steve Kerr] that I was going to respond like the champ I am.”

The Warriors sit 10th in the Western Conference after bouncing back from defeat at home against the Los Angeles Clippers, while the Jazz are 11th and have lost four games in succession.

Elsewhere, the Memphis Grizzlies claimed a shock 113-110 victory against the Milwaukee Bucks.

Ziaire Williams scored a career-high 27 points and rookie GG Jackson, 19, chipped in with 27 from the bench to help the Grizzlies, placed 13th in the Western Conference, to prevail against a Bucks side sitting third in the Eastern.

“It’s the best I’ve ever shot in my life,” Jackson said. “Once you have your jump shot, it opens everything else.”

There was further misery for the Portland Trail Blazers on home territory as the Minnesota Timberwolves recorded a 128-91 win.

Minnesota’s Anthony Edwards scored 34 points to extend the Trail Blazers’ losing streak to six.