His season-long slump alive and well in September Chase Headley still can’t put a finger on one thing that’s dogged throughout this frustrating campaign.

The Padres’ third baseman does know that one good swing can turn a bad night into a good one – just like that.

Sitting on three strikeouts Headley led off the ninth inning with a mammoth game-tying homer off the third deck of the Western Metal Supply Co. building triggering a last-ditch rally that ended with pinch-hitter Jesus Guzman’s walk-off single in a 4-3 win over the Colorado Rockies on Friday night before a crowd of 21476 at Petco Park.

“Obviously it was a tough night up until that point” said Headley who also homered Wednesday in his first action since missing six games with a sore lower back. “But it’s funny how this game works. (Rex Brothers) is a guy you don’t want to get deep in the count against. Two-oh looking for a fastball middle in and fortunately I got it.”

Headley’s blast came a half-inning after Huston Street served up a first-pitch homer to Todd Helton to open the ninth inning snapping a string of 20 1/3 scoreless innings for the Padres’ closer. The homer also gave the Rockies a 3-2 lead after the Padres bullpen turned in three perfect innings as the offense scratched and clawed their way to tie the game in the sixth inning despite going 1-for-7 with runners in scoring position.

But Street rebounded to retire the next three hitters and Headley bailed him out with his 10th homer of the season on a 2-0 fastball from Brothers the Rockies’ left-hander filling in at closer now that Rafael Betancourt has been lost for the season.

Kyle Blanks followed with a walk Alexi Amarista beat out a bunt for an infield single – and after Ronny Cedeno dropped a sacrifice bunt up the first base line and an intentional walk to Nick Hundley – Guzman singled inside the third-base line to end a night filled with all kinds of major league franchise and personal milestones.

There was Will Venable’s homer to start the game his eighth career leadoff homer to set a new franchise record and 15th homer this year at home the most ever hit at cavernous Petco Park. The first mark tops Quilvio Veras’ career numbers with the Padres and the second gives Venable one more homer than the 14 Adrian Gonzalez hit here in 2008 – before the fences were moved in for the start of this season.

Then there was the seven strikeouts that 23-year-old right-hander Burch Smith collected in five innings to become the first pitcher in Major League history to record 18 punch-outs in his first four starts totaling less than 13 innings.

Of course more important to Smith he held the Rockies to two runs on four hits and four walks after carrying an 11.37 ERA into the start.