Guzman singled to drive in the winning run in the bottom of the ninth after Headley tied the game with a leadoff homer in the inning, lifting the San Diego Padres to a 4-3 victory over the Colorado Rockies on Friday night.
"I think that game was Chase Headley," Guzman said. "He win the game because he changed the game. If he don't change the game, I don't hit it."
Headley was an unlikely hero considering he struck out in each of his first three at-bats against Rockies starter Juan Nicasio. But the switch-hitting Headley -- batting left-handed against Rex Brothers (2-1) -- hammered a 2-0 pitch to tie the game at 3-all.
"Obviously, it was a tough night up until that point but it's funny how this game works." Headley said. "Some of the best games you ever have are the worst games you ever have until one at-bat. Fortunately, I was able to get through those at-bats and come up with a fresh mindset."
Guzman's single with the bases loaded and one out, went over third base and scored Kyle Blanks with the winning run.
Huston Street (2-4) got the win despite allowing a go-ahead, solo home run in the ninth. Brothers failed to protect a 3-2 lead in the ninth.
"You make bad pitches, you get beat in this league," Brothers said. "I don't know if I made a single (good) pitch."
Headley tied the game with his 10th homer leading off against Brothers, a shot off the facing of the third deck of the brick Western Metal Supply Co. building in left field.
"He's a guy you don't want to get deep in the count with." Headley said. "I could afford to look for (a fastball). At 2-0, you're looking for a fastball, middle in and fortunately, he threw it there."
Todd Helton had given the Rockies a 3-2 lead in the ninth with a leadoff homer on Street's first pitch. Helton's 13th homer was the first run allowed by Street in 20 1/3 innings.
San Diego's Will Venable continued his hot streak with a leadoff homer in the first. It extended Venable's career best mark to 21 homers and established a Petco Park record for most homers (15) in the 10-year-old downtown ballpark.
Rockies center fielder Dexter Fowler left the game in the sixth inning when he reaggravated a left knee injury. Fowler appeared to hurt the knee when he stole second base in the fifth inning.
Nicasio allowed two runs -- one earned -- and four hits over six innings. The right-hander struck out seven and walked two.
After Venable's homer in the first and a triple by Chris Denorfia, Nicasio retired 13 consecutive batters until the Padres loaded the bases with one out in the fifth on two singles and a walk. Nicasio escaped trouble by getting Venable to ground into a double play.
Padres rookie Burch Smith allowed two runs and three hits in the first inning. He gave up one more hit over his five innings.
Smith became the first pitcher in major league history to strike out 18 or more in his first four career starts despite throwing less than 13 innings.
The right-hander came in with an 0-1 record and ERA of 18.41 in his first three starts covering 7 1/3 innings.
Colorado struck for two runs in the first. Fowler led off with a double, DJ LeMahieu followed with an infield single and Troy Tulowitzki doubled to score one run. Michael Cuddyer grounded out to score the second run.
San Diego tied it at 2-all in the sixth. Denorfia drew a leadoff walk. Jedd Gyorko then hit a slow roller to third base that LeMahieu fielded and threw out the rookie.
Denorfia kept going to third and first baseman Helton's throw went high over third base and bounced against the fence in foul territory. Catcher Wilin Rosario, backing up the throw, slid to pick up the ball, and from his knees, fired the ball to Nicasio. But Denorfia slide wide to avoid the tag and just got his hand on the corner of the plate.
Rockies RHP Roy Oswalt, activated off the 15-day DL on Friday, will be "piggybacked" behind RHP starter Chad Bettis on Sunday. Oswalt is 0-4 with a 7.64 ERA in four starts. ... Padres OF Cameron Maybin underwent arthroscopic surgery on his right wrist Friday to remove some loose particles, according to manager Bud Black. Maybin played in only 14 games this season. ... Colorado RHP Tyler Chatwood (7-4, 3.29 ERA) faces San Diego RHP Tyson Ross (3-7, 2.99) on Saturday night.