So, with the game on the line, he left it to the veteran to give the Suns a lift in the Western Conference standings.
Richardson connected on a floater from the foul line with 0.7 seconds left to complete the Suns' rally from a 10-point deficit, and Phoenix snapped the Oklahoma City Thunder's nine-game winning streak with a 104-102 victory on Tuesday night.
"You just go back and look at the numbers," Gentry said. "When he plays great, we very seldom ever lose."
Amare Stoudemire scored 30 points and Richardson had his second double-double of the season with 20 points and 13 rebounds for the Suns, who were down 10 with 3 1/2 minutes to play. He also forced a key turnover late, tying up James Harden and then winning the ensuing jump ball.
And Richardson's game-winner helped Phoenix improve to 17-2 when he scores at least 20 points this season.
The performance couldn't have come at a better time for the Suns, who were playing their first game without point guard Steve Nash. The two-time MVP did not make the trip to rest injuries to his back and abdomen.
After a timeout, Gentry put the ball in Richardson's hands and let him create. He blew past Thabo Sefolosha, the Thunder's defensive stopper, and squeezed past Russell Westbrook before letting the ball fly.
"Teams are real reluctant to be so aggressive when the game is tied and it's the last shot," Gentry said. "We said, 'If you're not wide open, then drive it to the basket and see what you can get.' He did a great job of splitting the two guys and getting into the paint."
Kevin Durant scored 36 points and Westbrook had 21 points and 10 rebounds for the Thunder, who had narrow escapes in their previous two wins.
Phoenix has won nine of its last 11 games to move past the surging Thunder into fifth place in the West.
"It's our best win of the year, by far, I think. Especially playing without Steve," Gentry said. "To come in here and be able to beat this team without Steve, it's a heck of an accomplishment. It's a big plus for our guys."
Oklahoma City had rallied from six points down in the final 65 seconds to beat the Knicks on Saturday and then edged Minnesota by two after blowing a big lead on Sunday.
The Suns found a way to win this time, squandering a 15-point lead in the second half before digging out of a 98-88 hole down the stretch. Oklahoma City was bidding for its first 10-game winning streak since November 1996, when the franchise was in Seattle and coming off an appearance in the NBA finals.
"A streak like that won't last the rest of the season. You'd like it to, but this league's too tough for something like that," said Durant, who has scored at least 25 points in 29 straight games.
Grant Hill added 20 points for Phoenix and Goran Dragic -- making only his third career start at point guard with Nash and backup Leandro Barbosa (wrist surgery) both out -- had 16 points and a career-high 10 assists.
Jared Dudley hit a 3-pointer with 3:17 to go, Stoudemire followed with a dunk and added another basket inside before Hill hit two free throws to get the Suns within 100-97 with 1:26 remaining.
After Jeff Green made a pair of free throws for the Thunder, Stoudemire emerged from a scramble for the ball and converted a three-point play to cut the deficit to 102-100. Durant missed a jumper from the top of the key for Oklahoma City, and Westbrook fouled Richardson on the rebound with 40.2 seconds left to set up his tying free throws.
Green, who had 16 points, missed a desperation 3-pointer at the buzzer as he fell out of bounds toward the Phoenix bench.
"I think this is a big game, knowing that they were a game ahead of us in the standings and how important this game was for us," Stoudemire said. "Playing without Steve and Leandro, it was a challenge for us but I think we came out and rallied together and played great team basketball."
Antonio Anderson, who signed a 10-day contract Monday, was inactive for his first game with Oklahoma City. "You're not in college anymore. You're not going to be spoiled," Anderson said. "You know they're going to expect you to work, and that's what I'm here for. I'm not asking for anything. They gave me an opportunity, and that's just enough. I'm just going to work hard enough, and hopefully they like what I have to give." ... The Suns remain the only NBA team unbeaten at the Ford Center. They're 3-0 against the Thunder and also won their only two games against the New Orleans Hornets in Oklahoma City following their hurricane-forced relocation.