The Cardinals led, 5-3, before the Padres touched Flores for three runs on three hits in the seventh. Flores, whose ERA ballooned to 6.97 with the rocky outing, was taking full blame for the loss.
"No one wants to be the guy that you can absolutely look at and know that that's a big reason why you lost the game," Flores said. "We'll see what happens tomorrow."
On Thursday, Cardinals reliever Ray King took the loss in an 8-3 loss to the Padres. That game was tied 3 heading into the eighth inning before King gave up two runs.
The Padres didn't have near the same relief problems on Friday, as five relievers combined to allow the Cardinals just one run after they chased Padres starter Darrell May after 3 2/3 innings.
But the Cardinals did not score after the sixth inning, and Trevor Hoffman pitched the ninth for his 400th career save. Hoffman struck out pinch-hitter Larry Walker looking, got David Eckstein on a grounder to third and caught So Taguchi looking to pick up the historic save. He is just the third pitcher in Major League history to reach the mark. Lee Smith (478) and John Franco (424) top the list.
"I admire his professionalism as much as anybody, and he's been an outstanding pro for a long time," Cardinals manager Tony La Russa said of Hoffman.
Rather than harp on his bullpen -- which is without closer Jason Isringhausen -- La Russa gave tipped his cap to the Padres, who have won five straight games.
"Give them credit, they got the hits with two outs," La Russa said. "Rather than beat up our bullpen, I give the Padres credit."
Flores looked like he was going to escape unscathed in the seventh, as he retired two of the first three hitters. But with a 1-2 count on pinch-hitter Xavier Nady, Flores hit the right-handed-hitting Nady on his back foot with a sharp-breaking slider.
"It was a back-foot slider that hit the back foot. I wanted to go back there and I just went too far," Flores said. "I went in there once for a strike and was trying to go in there a little deeper."
With runners at first and second, Brian Giles drilled a two-run triple to the gap in left-center to tie the game at 5. Mark Sweeney, who had a pinch-hit homer in the sixth, followed with a single to center for the 6-5 lead.
La Russa said hitting Nady turned out to be as big a play as any.
"That was a big out. If [Flores is] tired, he hangs it, he doesn't bounce it," La Russa said of the slider that hit Nady. "That was a tough break, because he had the hitter in a good count for us, and then you don't have to face the other guys that got the big hits. But that's the game of baseball. You've got to get that third out, and we didn't get it."
Suppan went 5 2/3 innings, allowing three runs on six hits, striking out four and walking three. Albert Pujols went 0-for-3 and saw his hitting streak end at 16 games.
Trailing 1-0, Cardinals left fielder Reggie Sanders went the opposite way for a solo home run just inside the right-field foul pole to lead off the second inning and tie the score.
After going down quietly in the third inning, the Cardinals erupted in the fourth for three runs on five hits to knock out May. After Scott Rolen's double off the base of the wall in left-center, Jim Edmonds singled up the middle to break the tie. Einar Diaz added an RBI single, and Eckstein chipped in with a ground-rule double for an RBI to make it 4-1 and send May to the showers. If Eckstein's ball would not have gone in the seats, Suppan might have also scored on the play.
"That would have been an extra run, but that's part of the game," La Russa said.
The Padres cut the lead to 4-3 in the sixth on pinch-hitter Sweeney's two-run homer that hit off the right-field foul pole.
"Basically it was a changeup that cut back over the plate, and he was able to put some good wood on it," Suppan said of Sweeney's home run.
"I was hoping it would go foul."
The Cardinals took a 5-3 lead in the sixth thanks to some hustle by Edmonds. After a leadoff walk, Edmonds was on the move on a 3-2 pitch to Mark Grudzielanek, who grounded sharply to third baseman Sean Burroughs. Burroughs made a backhanded stab and made the long throw to first to get Grudzielanek, but Edmonds kept on chugging and barely slid safely into third. Diaz then followed with a bloop single to right for the lead.
Alan Gerdes is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.