Rudy Gay had 22 points, and Conley scored 14 of his season-high 16 points in fourth quarter to help the Grizzlies beat the Oklahoma City Thunder 108-102 on Wednesday night for their first winning streak of the season.
Mayo, the NBA's highest-scoring rookie and the team's leading scorer, went to the bench late in the third quarter with four fouls and his backup never let him get back on the floor.
Memphis trailed most of the way until Conley, a second-year point guard out of Ohio State, started carving his way into the lane repeatedly.
"It was a big step, a huge step, because not too many times have I been the one to have the ball in my hands and be [isolated] and things like that," Conley said. "That was a different kind of game for me, so I just tried to take advantage of it as best I could."
Conley credited coach Marc Iavaroni and his staff for trusting him and three other backups who joined Gay on the court for the fourth quarter.
"They ran a lot of plays for me, tried to get me in the paint and create a lot of shots for people and for myself," Conley said. "I think that really opened it up for everybody and it really got our momentum."
Mayo added 18 points in the first three quarters to pass Magic Johnson for the third longest streak of double-figure scoring games to start a career at 22. Only Dan Issel (27) and Bobby Jones (24), who played for the Denver Nuggets in the franchise's first season in the NBA in 1976, had longer streaks.
Kevin Durant scored 28 points, Russell Westbrook added 15 and Jeff Green had 13 for Oklahoma City, which got one of its league-low two wins at Memphis on Nov. 29. Desmond Mason, Nick Collison and Joe Smith also scored 10 apiece.
"It's the most miserable season I've ever been a part of: 2-21. It's tough," Collison said. "Hopefully we start winning and things will go a lot better."
Oklahoma City broke through its trend of slow starts and led at the end of the first quarter for only the sixth time this season, and then started pulling away with a 13-0 run that Green finished with a layup for a 44-25 lead with 6:41 to go before halftime.
Collison stretched the lead to 21 with a two-handed jam off a pass from Westbrook.
"If we were able to continue playing like that and continue to get stops like that, obviously things would have been different," Collison said. "So, I guess we are showing signs, but until we do it consistently and win a game, it's not going to matter much."
But then the Grizzlies, who missed 21 of their first 29 shots, roared back with nine straight points and finished the half on an 18-4 run to get to 55-48.
Memphis finally went ahead for the first time since the opening 2 minutes when Hakim Warrick scored from the left block with 9:05 left for an 87-85 lead. The teams then swapped the lead three more times before Conley cut into the lane for a layup that made it 95-94 and started a string of six straight points for the Grizzlies.
Iavaroni, who has been shuffling his lineup lately anyway, decided to stick with his four backups.
"It's all about energy and it's what you feel out there, and the guys on this team are mature enough to understand that I'm not keeping people off the court necessarily as I am keeping people on the court," Iavaroni said.
"That's what keeps people on the court: playing hard and smart together. And I'll ride it as long as I can until it needs a change."
Mayo, who was averaging 21 points, remained on the bench with a towel draped around his shoulders even after Westbrook hit two free throws to get Oklahoma City back within 99-98. Instead, it was Conley, Gay, Quinton Ross, Marc Gasol and Greg Buckner who were on the court to score nine of the next 11 points and put the game away.
"It means a lot to me as a player because you don't get too many chances. You've got to be able to establish yourself sometime," Conley said. "To come in in the fourth quarter and make big plays is always a big deal for young players. It was a great opportunity for me and I'm glad I was in the game."
The Grizzlies regained the first-round pick they had traded to Washington last year with a three-team trade that sent backup G Javaris Crittenton to the Wizards and a conditional second-round pick to New Orleans. ... Thunder F Chris Wilcox dislocated his left ring finger midway through the first quarter and did not return. ... Thunder F Joe Smith, who broke his nose in the preseason, played for the first time this season without a clear, protective mask on his face. ... Oklahoma City's 21-point lead was its largest of the season, surpassing a 16-point lead in a loss to Phoenix on Nov. 25.
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