The Thunder star joined Oklahoma City back in 2019.
Shai Gilgeous-Alexander delivered the winning points late in double overtime as the Oklahoma City Thunder opened their championship campaign with a 125-124 victory over the Houston Rockets.
The reigning MVP scored 35 points, including two clutch free throws with just mere seconds remaining in the second overtime, securing the titleholders a positive start.
Houston's Alperun Sengun led all scorers with 39 points and also connected on a personal-best five shots from beyond the arc.
But Chet Holmgren, who contributed 28 points of his own, was instrumental alongside match-winner Gilgeous-Alexander.
"Grit and defense," Gilgeous-Alexander commented of their performance. "We know that when we do it on defence we give ourselves a chance no matter what's going on—shots, misses, fortune or misfortune. We did sufficient defence to get the win. We're pretty rusty, but it's a good start."
Before the tip-off, Oklahoma's title banner was unveiled at their home court, while the squad were presented with their title rings.
The Thunder defeated the Pacers in last season's best-of-seven NBA Finals. It was their first title since the team relocated in 2008 to OKC from Seattle, who had claimed the 1979 title.
The Pacers will have the chance to secure some early revenge on Friday when they host Oklahoma, while the Rockets are back on court on the identical day at the Detroit Pistons.
In other action, a huge effort of 43 points, 12 boards and nine assists from Luka Doncic was not enough to stop his new team the Lakers from suffering a 119-109 loss against the Warriors.
Jimmy Butler scored 31 points and Golden State's sharpshooter added 23 for the road team.
The Lakers were without the NBA's all-time leading scorer James as he recovers from sciatica.