Phoenix Suns thrashed Dallas Mavericks 110-80 on Tuesday night to seize the advantage as they took a 3-2 lead in their best-of-seven series.
Phoenix can be backed at 23/10 to win the NBA Championship outright, while Eastern Conference top seeds Miami Heat can be backed at 11/2.
The Suns won the first two games in Phoenix, but were pegged back in Dallas as the Mavs won back-to-back games to draw level.
The Mavs did lead at the end of the first quarter and the first half was competitive as Phoenix led by just three points at the midway point, but the top seeds stepped up a gear and outscored Dallas 61-34 in the second half to record a blowout victory.
Phoenix guard Devin Booker, who led the game in scoring alongside Mavs star Luka Doncic with 28 points, says the Suns benefitted from some tactical readjustments from NBA Coach of the Year Monty Williams after they moved to within one win of the Western Conference finals.
"We study film," said Booker, via USA Today. "Coach is coming in with adjustments, we make them and we follow them."
Game 6 of the series takes place in Dallas on Thursday.
In the East, the Heat responded after back-to-back defeats to Philadelphia 76ers with a blowout win of their own as they secured a 120-85 win in Miami.
The Heat opened up a 12-point lead at the end of the first quarter and were never behind after the opening exchanges, as they outscored the Sixers by 20 points in the fourth to secure a huge victory.
Miami will progress to the Eastern Conference finals if they can claim a victory in Game 6 in Philadelphia on Thursday.