SAN FRANCISCO -- After a horror-filled three days that defied all rational explanation, the Giants were left shaking their heads Sunday and hoping this won't be a weekend that winds up living in infamy come September.
For the third straight day, the heretofore sturdy Giants coughed up a late-inning lead, and they wound up losing 8-7 to the Colorado Rockies at AT&T Park.
One bullpen blowup could be stomached. Two, OK, maybe that's a little troubling. But three collapses in three days? Try finding a similar series meltdown in the franchise's annals, even with some of its worst teams. The Giants still cling to baseball's best record and a 6½-game lead in the National League West, but their grip is considerably less firm.
"That's what's so tough to take about this series," said manager Bruce Bochy, whose club lost for the sixth time in seven games and finished a 10-game homestand at 4-6. "We're a few outs from a sweep and instead we get swept. That's never easy, but hey, you've got to put it behind you."
That could be easier said than done, because nobody saw this derailment coming. The bullpen has been lockdown solid all season, to the degree that before this series started, the Giants were 34-1 leading after seven innings and 35-0 after eight. To make this belly flop all the more strange, the Rockies were a team without much comeback cred -- 0-26 when trailing after seven and 0-29 after eight.
But over these three days, the Rockies were the kings of clutch against a Giants bullpen that inexplicably wasn't much. Sunday's victim was right-hander Juan Gutierrez, who was entrusted with a 7-4 lead entering the top of the eighth, and that seemed a safe call considering Gutierrez had not given up a run in 16 home appearances covering 16 innings this year.
But Gutierrez was toasted for four runs. He didn't get any help from his defense, which botched a tailor-made double play that would have ended the inning with the Giants still leading. Moreover, the Giants still had a favorable lefty-lefty matchup with Javier Lopez facing pinch-hitter Justin Morneau with two outs, but Morneau punched a Lopez fastball down the left field line to score the tying and winning runs.
"I thought I threw a pretty good pitch at the time," Lopez said. "Maybe it caught a little bit too much of the plate, but I think the goal there was to make him go away, and he just squeaked it down that line."
Lopez, one of the most cerebral Giants, was as baffled as anyone about how this series turned out.
"It's not something you see normally see happen in this game over a three-game stretch like we had," he said. "So it's difficult."
Starter Madison Bumgarner, who battled through seven innings, got back-to-back home run support from Hector Sanchez and Pablo Sandoval, hit a solo home run himself in the fifth inning and made what appeared to be a key defensive throw for an out in the seventh, was even more graphic.
"This stinks for us," Bumgarner said. "We should have won a lot of these games we lost on this homestand. We're just going through a tough stretch right now. You're going to have adversity throughout the year, and we're not really playing that bad of ball right now, but for some reason, we keep finding ourselves on the losing side."
If there's any reasonable explanation, it's that the bullpen might be a bit overworked. Closer Sergio Romo, who gave up ninth-inning leads in the Friday and Saturday games, wasn't available Sunday. Jean Machi pitched for a fourth straight day. Had Jeremy Affeldt been called in -- and he was warming up -- it would have been his third straight day.
"We're where we're at because of what this bullpen's done, but they have been worked a lot, I'll say that," said Bochy. "So (Monday's) day off is coming at a good time."
It's coming at a good time for other reasons, too. Center Angel Pagan had to be scratched from the starting lineup with lower back stiffness, and his status heading into a five-game trip starting Tuesday against the Chicago White Sox was unclear.
Meanwhile, catcher Buster Posey took a hard foul tip off his mask -- his second of the week -- and was removed from the game after the top of the fourth. Posey said after the game that he went through a battery of concussion tests, that "everything's good" and that he didn't have a headache. But he added that the Giants will monitor his progress Sunday night and Monday, because if he's unable to go, the Giants will have to make a move. Sanchez is the only other catcher on the 40-man roster.
Giants (Matt Cain 1-4) at Chicago White Sox (John Danks 5-5), 5:10 p.m. CSNBA