Nash switched into pre-Shaq mode to guide Phoenix back from a 12-point deficit in the fourth quarter, and Matt Barnes finished it off by hitting the game-winning 3-pointer from the left wing with 25.7 seconds left as the Suns beat the Thunder 99-98 Tuesday night.
"It sure looks like we're just a little too reliant on Shaq. We're just not quite comfortable playing without him the way we used to play because we spend so much time trying to incorporate him," Nash said, then referred to coach Terry Porter. "Terry's been working with us and trying to get us to get back to doing some of the things we used to do, things that we're good at, when he's not on the floor."
Amare Stoudemire finished with 22 points, Nash had 20 points and 15 assists and Barnes scored 16.
Kevin Durant scored 29 points and Chris Wilcox added a season-high 18 as Oklahoma City (1-14) led by 16 as late as the final 2 minutes of the third quarter. Still, the Thunder dropped their 12th straight game.
Stoudemire beat the third-period buzzer with a 3-pointer, and the Suns then crashed the boards and relied more on the pick-and-roll game and Nash's creativity to dig their way out of an 86-74 hole with 11 straight points.
Nash hit a 3-pointer and a jumper during the run and then found Boris Diaw open under the basket for a right-handed dunk that pulled Phoenix to 86-85 with 5:11 to play.
Durant answered with a jumper at the other end, and it seemed the Thunder might keep the Suns at bay when Jeff Green converted a three-point play off a layup in transition to stretch the lead to 91-87.
Durant added a 3-pointer to make it 95-89, but Nash scored Phoenix's next seven points to tie it at 96 with a jumper from the right side with 48.5 seconds left.
Wilcox then scored inside for the Thunder before Barnes connected for the Suns' only lead of the second half.
"I knew I was going to get the ball because they all rolled to Amare," Barnes said. "I knew I was going to get the shot, so I had to knock it down."
The Thunder had two final chances to win, but Durant and Russell Westbrook both missed shots on their final possession. After Nash was fouled outside of a bonus situation with 8.4 seconds left, the Suns scrambled around the court to run out clock without getting fouled again.
Oklahoma City lost its second consecutive game since Brooks took over after P.J. Carlesimo was fired. In each of the last two games, the Thunder have gotten out of the habit of getting blown out and at least been competitive down the stretch.
"The process is in place," said Brooks, a former assistant coach. "We just have to continue to figure out some things and work on our execution."
Phoenix, which got 11 points apiece from Robin Lopez and Diaw, is continuing to adapt to Porter's coaching style and the addition of O'Neal late last season. He's planning to take days off in back-to-back sets to preserve his health, and that only adds another situation for the Suns to figure out.
"We're finally kind of getting back to a rhythm that we had without Shaquille," Nash said. "Terry's been urging us to get back there. We have spent a lot of time working on the other stuff, and we've lost our rhythm there a little bit. We found it a bit tonight."
And it was Nash, the two-time NBA MVP, leading the way. He hit all five of his shots in the fourth quarter for a strong finish that left him two rebounds shy of a triple-double.
"He looked like old Steve," Barnes said. "He took over in every aspect. ... We need Steve just to play his game for us to be the best team we can be, and tonight he did that."
Westbrook scored 15 points, Green had 13 and Damien Wilkins added 10 in his second game as a starter after Brooks moved to a smaller lineup with his three 7-footers on the bench. Earl Watson had a season-high 13 assists.
Westbrook scored 12 points, including a pair of three-point plays, as the Thunder went on a 21-6 run to take a 52-36 lead in the second quarter. They equaled that lead again in the third after the Suns had cut it in half.
"We feel pretty good about where we're going. We just can't take any steps backward," said Thunder forward Joe Smith, who credited a more inclusive offense for creating a higher energy level for the team. "We've got to continue to improve, continue to move forward."
Civil rights activist Clara Luper, who participated in a peaceful sit-in at a segregated lunch counter in downtown Oklahoma City in 1958, was honored at halftime as Devon Energy Corp.'s Community Hero. ... The Suns lost the other game Shaq missed, on Nov. 7 at Chicago. It also was the first of back-to-back road games. ... Phoenix reserve Leandro Barbosa returned after missing five games to return to Brazil following the death of his mother. He had four points on 1-for-6 shooting.