Toronto made a 22-point fightback to beat the Spurs 123-116 in overtime while the Cleveland Cavaliers sparkled as well, snapping a 12-game regular-season losing streak to Golden State dating to Christmas 2016.
Durant added five assists, four rebounds, three blocked shots and a steal to power the Suns past the host Pistons 120-106.
"He was terrific, scored the ball every way you can, really wants it," Suns coach Frank Vogel said. "Just a really terrific performance. He's really good at basketball and he showed it tonight."
The Suns outscored Detroit in every quarter as Eric Gordon contributed 21 points and eight assists for Phoenix, which snapped a three-game losing skid.
"We're excited because we finally got a win," Durant said.
Cade Cunningham led Detroit with 26 points in the first regular-season matchup between the Suns and their former coach Williams.
After Williams was fired as the Suns' coach following a second-round playoff exit last season, Detroit signed him to a six-year deal worth $78.5 million.
The Suns were without Bradley Beal, sidelined by back spasms, and Devin Booker, out with a calf strain.
Raptors rally
At Cleveland, Donovan Mitchell scored 31 points and Darius Garland added 24 to power the Cavaliers over Golden State 115-104.
"The biggest thing for us is that we put together a full game," Mitchell said. "We fought hard. That's a tough team. They have a lot of guys who have won championship rings and we're trying to get to that level. We've got to continue this momentum."
Evan Mobley added a game-high 16 rebounds for the Cavs.
"He was dominant," Mitchell said.
Stephen Curry led the Warriors with 28 points, hitting 7-of-11 shots from 3-point range, while Draymond Green added 18 points for Golden State, which saw a five-game win streak ended.
At San Antonio, 26-year-old English forward Anunoby scored 24 points for the Raptors, hitting a career-best seven 3-pointers to spark a shocking comeback over star French rookie Victor Wembanyama's Spurs.
Scottie Barnes sparkled for Toronto with a game-high 30 points, 11 rebounds, six assists, three steals and three blocked shots.
Anunoby sank the tying basket off a rebound with one second remaining to send the game into overtime at 110-110. His 3-pointer in the extra session game Toronto a 118-112 edge.
German guard Dennis Schroder added 24 points for the Raptors.
Keldon Johnson led San Antonio with 26 points while Zach Collins added 21 points and 11 rebounds and Wembanyama contributed 20 points, nine rebounds, five blocked shots and four assists for the Spurs.
Memphis finally wins
Desmond Bane scored 30 points and Jaren Jackson added 27 to spark previously winless Memphis to victory, the Grizzlies improving to 1-6 with a 112-100 triumph at Portland.
At Dallas, Slovenian guard Luka Doncic had 23 points, 12 rebounds and nine assists to spark the Dallas Mavericks over Charlotte 124-118.
Kyrie Irving had 18 points and 10 assists for the Mavs, 5-1 overall and 3-0 at home, while Grant Williams scored 18 points and Dereck Lively added 15 points and 14 rebounds.
LaMelo Ball led the Hornets with a triple double of 30 points, 13 assists and 10 rebounds.
