Jeff Chiu, Associated Press
SAN FRANCISCO — Troy Tulowitzki's home run in the 10th inning could have been the perfect cap to another stellar day near his hometown.
Instead, Colorado's slugging shortstop was upstaged by one of the rarest plays in baseball.
Angel Pagan hit a game-ending, inside-the-park home run with a runner aboard off closer Rafael Betancourt in the bottom of the 10th, spoiling Tulowitzki's day in a 6-5 loss to the San Francisco Giants on Saturday.
"It would have been a lot worse if we would have lost (Friday) and then have this on top of it," Tulowitzki said after Colorado's three-game winning streak ended. "We're still 1-1 in this series and have a chance to win it, which hasn't happened too often for this organization for a while."
The Rockies had won four straight against the defending World Series champions and were in position to extend the streak until Pagan sent a drive that hit the base of the oddly angled wall in right-center and bounced high over the head of right fielder Michael Cuddyer.
The ball caromed away from Cuddyer as the speedy Pagan raced around the bases and slid home ahead of the relay from second baseman D.J. LeMahieu to hand Colorado its second loss in eight games.
It was Betancourt's first blown save in 11 chances this season.
It also was the first inside-the-park home run in the majors this year and the first to end a game since Tampa Bay's Rey Sanchez did it in the 10th inning against Colorado on June 11, 2004, according to STATS.
"You're not thinking that when the ball comes off the bat, but the configurations of the ballpark put you in a situation where it can kick any way out there," Rockies manager Walt Weiss said. "That's what it did."
Tulowitzki's homer was his 10th of the season. It came off Giants closer Sergio Romo (3-2).
Tulowitzki, who grew up 30 minutes south of AT&T Park, went 2 for 5 to extend his hitting streak to 10 games and raise his average to .338 — the third-highest mark in the NL.
He also had a good view of Pagan's game-winning drive.
Brandon Crawford drew a leadoff walk from Betancourt (1-2) to begin the inning and was sacrificed to second before Pagan connected.
"It was possible it had home run distance so you're thinking it could be a game-winner, and it took a good bounce for them," Tulowitzki said. "To go ahead and then to lose the game is tough. We knew we were going to be in for it, too. It's not like we get ahead by one and you go out there like, 'Hey, we got it.'"
Carlos Gonzalez homered among his three hits and drove in two runs for the Rockies. Cuddyer and Jordan Pacheco also drove in runs.
Rockies starter Juan Nicasio went five-plus innings, allowing two runs and seven hits. He walked one and struck out two.
"I threw a lot of two-seamers and had control to send in my fastball for a strike," Nicasio said.
Giants manager Bruce Bochy was ejected in the bottom of the eighth by plate umpire Alfonso Marquez for arguing a call at third base after Marco Scutaro appeared to dodge Nolan Arenado's tag on a throw from the outfield.
Marquez called Brandon Belt out at home on a close play in the seventh.
Hunter Pence's RBI double in the sixth ended San Francisco's 24-inning scoreless streak against Colorado pitching. Crawford's sacrifice fly and Scutaro's bases-loaded walk brought the Giants within 4-3.
Dexter Fowler opened the game with a double and, one out later, Gonzalez hit the first pitch into McCovey Cove beyond the right-field wall.
The Rockies added a pair of runs in the fourth on consecutive doubles from Tulowitzki and Cuddyer, and a one-out single by Pacheco.
Cuddyer has three hits — all for extra bases — and four RBIs in his two games back from the disabled list.
The Giants loaded the bases in the first inning but failed to score. Nicasio retired 13 of his next 16 hitters, twice stranding runners in scoring position.
NOTES: Gonzalez became the first Rockies player to have a "splash hit" into McCovey Cove. It was the 27th splash hit by an opponent and the 90th overall since the ballpark opened in 2000. ... Rockies RHP Jon Garland (3-5, 5.19 ERA) pitches Sunday's series finale. He last faced the Giants on Sept. 9, 2010. ... RHP Matt Cain (3-2, 5.12) starts for the Giants. He will be facing the Rockies for the 30th time.