Luka Doncic of the Dallas Mavericks drives to the basket against the Phoenix Suns on May 15, 2022 in Phoenix, Arizona. Photo: VCG

Luka Doncic scored 35 points as the Dallas Mavericks completed a stunning upset of the top-seeded Phoenix Suns with a jaw-dropping Game 7 rout in Arizona on Sunday.

Slovenian star Doncic was in magnificent form as the Mavericks romped to a 123-90 victory at Phoenix's Footprint Center to clinch the best-of-seven Western Conference semifinal series 4-3.

The Suns entered the playoffs as the best team in basketball, with a regular season record of 64 wins and only 18 defeats.

But a playoff campaign which seemed poised to see a repeat of last season's advance to the NBA Finals instead ended in disarray and catcalls from their own fans.

Doncic finished with 35 points, 10 rebounds and four assists, while Spencer Dinwiddie gave valuable scoring support with 30 points, including five three-pointers.

Jalen Brunson also posted double figures with 24 points as Dallas advanced to a Western Conference finals showdown with the Golden State Warriors starting Wednesday.

"Amazing," Doncic said after the win. "I don't know what to say but this was amazing to win. 

"Everybody played as hard as they can. We didn't have any days off. An incredible team win. I don't have nothing more to say," added Doncic, who is looking forward to facing Golden State.

"They're a championship team. It's going to be really tough again. I'm just really happy we got this win tonight. 

"I'm going to enjoy this win tonight and then tomorrow I'll think about Golden State."

Phoenix, who had led 2-0 and 3-2 earlier in the series, were left reflecting on a no-show from their star names.

Suns star Devin Booker made just 11 points while Chris Paul finished with 10 points.

The Mavs effectively sealed the contest with a devastating first half display that included 27 points from Doncic.

The Suns trudged off at halftime trailing by an incredible 57-27, with the home fans booing in disgust as the top seeds returned to the locker room.

After surging into a 10-point lead at the end of the first quarter, the Mavs dropped the hammer in the second period to race into a 30-point lead by halftime.

With Doncic in commanding form, Phoenix simply had no answer to the Dallas offense, who went 19-of-40 from the field in the first two quarters.

Things barely improved for Phoenix after halftime, with the Dallas offense once again raining in three-pointers to maintain their stranglehold.

Another Doncic three-pointer left Dallas an eye-popping 41 points clear at 83-42 as the torture continued for the home side.

Suns fans could be seen filing out of the stadium before the start of the fourth quarter, admitting defeat with their team trailing 92-50.

Phoenix coach Monty Williams said his team had saved their worst performance of the season for their most important game.

"I just told them how badly I hurt for them," Williams told reporters shortly after addressing his team.

"I know they didn't want to play that way. We basically played our worst game of the season tonight. I know how bad they wanted it, they just could not execute tonight, could not make a shot early on. 

"And that messed with us a little bit, and Dallas played their tails off from start to finish.

"It's a part of manhood. There are days when it doesn't go your way and you've got to stand there and show character and integrity and take it. That's life."