And with every open shot the Phoenix Suns allowed, the Pacific Division champions exposed what's probably their biggest flaw heading into the postseason.
Richardson scored a season-high 36 points and hit a franchise-record eight 3-pointers, and the Warriors rolled from a 45-point first quarter Thursday night to a 124-119 victory.
Stephen Jackson scored 29 points and Baron Davis added 21 points, 12 assists and eight rebounds as the Warriors took a 25-point lead in the third quarter, but blew most of it in the fourth before hanging on for an important win for their playoff hopes.
With Richardson leading a remarkable offensive outing in the first three quarters, Golden State moved within one game of the Los Angeles Clippers for the Western Conference's final postseason spot. Though they won just twice in a five-game span against probable playoff teams, the Warriors (34-39) aren't giving up on their first playoff berth since 1994.
"It shows what our character is," Richardson said. "We just put everything out there, left everything on the court. After my first shot went down, it felt good. Then the second went down, and after that, I knew it was going to be a good game for me."
The Warriors set season highs for points in a quarter as Richardson scored 19 in the opening period, and they had a season-high 77 by halftime.
Richardson was awful in the Warriors' previous two games, going scoreless in 29 minutes during Golden State's home loss to San Antonio on Monday. Before the game, Warriors coach Don Nelson said Richardson hasn't been fully healthy all season after undergoing knee surgery shortly before training camp.
Richardson didn't score in the fourth quarter, but his 12 rebounds also were a season high.
Leandro Barbosa scored 27 points for the Suns, who lost in Northern California for the second time in five days with another unpleasant defensive effort. Boris Diaw, Barbosa and three Phoenix reserves trimmed Golden State's 25-point lead to five in the fourth quarter of the Suns' first loss to Golden State in four meetings this season.
"We've got to be a little careful," Suns coach Mike D'Antoni said. "They're fighting for the eighth spot, and we're not. Sure, we're trying to stay ahead of San Antonio, but when they come out like that and have that juice, and the crowd is behind them, it would have been hard for anybody."
Diaw scored 18 points and Amare Stoudemire added 17 points and 11 rebounds for Phoenix, which already has clinched its third straight Pacific Division title. But the Suns' defense didn't look any more playoff-ready than it did in their exits from the previous two postseasons.
Steve Nash had 14 points and nine assists, while Shawn Marion managed just 10 points. Nash, Marion and Stoudemire all sat out the fourth quarter as the Suns' second-teamers made it interesting against Golden State's starters.
"They did everything perfect, all of their players," Barbosa said. "It was a great game for them. They've been playing to qualify (for the playoffs). I think they will. They're a good team, they have a good coach and they're doing a really great job."
Richardson broke the club record of seven 3-pointers, which he held along with six other players. He was the second player in five days to set his franchise's record for 3-pointers against the Suns, after Mike Bibby's Sacramento-best nine 3-pointers in the Kings' 107-100 win on Sunday.
The Warriors scored 18 points in the first 3 minutes with four 3-pointers. Golden State had 30 points in the first 5 1/2 minutes, including 16 by Richardson on four 3-pointers and 6-for-6 shooting.
Golden State finished the quarter leading 45-33 -- its highest-scoring quarter in more than 15 years. The Warriors led 77-63 at halftime with 60 percent shooting and nine 3-pointers in their highest-scoring first half since April 1, 1994.
Richardson broke the franchise record on a 3-pointer from the corner with 1:49 left in the third quarter, and Golden State led 109-86 entering the fourth.
Barbosa and Marcus Banks got the Suns within 122-116 in the final 2 minutes, but Davis stripped the ball from Banks and drove for a layup with 58 seconds left.
"It doesn't matter that we almost blew a lead," said Nelson, who used his league-high 36th different starting lineup. "The only thing that is important is that we got a win that we needed against a good team."
Richardson's five 3-pointers in the first quarter tied the franchise record set by Joe Hassett on March 28, 1981, against Denver. ... The first quarter was the Warriors' highest-scoring frame since posting 46 points in the first quarter against Sacramento on Nov. 2, 1991.