Pinch-hitter Chris Denorfia hit a two-run homer in the bottom of the ninth inning to lift the San Diego Padres to a 2-1 win over the Cincinnati Reds in the opener of a three-game series at Petco Park.
Following a leadoff walk to Yonder Alonso, Denorfia jumped on a first-pitch fastball from Reds closer Aroldis Chapman (3-4), sending it over the wall in straight-away center field for his first career walk-off blast.
"Everybody's got to be ready for the fastball. I mean you got to be ready," said San Diego manager Bud Black. "If (Chapman) spits out a good slider, you're in trouble, but you got to be ready for the fastball."
Denorfia's home run was the first San Diego hit since the third inning and the team's only extra-base hit.
"We shouldn't have been in that situation. We left a lot of men on base again," said Cincinnati manager Dusty Baker.
Everth Cabrera singled twice and reached base three times to begin an inning for San Diego, which has won three in a row and six of eight games overall.
Padres starter Sean O'Sullivan battled some control issues to pitch six innings. He allowed a run on five hits and five walks. Luke Gregerson (5-5) tossed a 1-2-3 ninth to get the win.
Cincinnati's Mike Leake was in line to win his fourth straight start after holding the Padres to four hits over seven frames.
Joey Votto, Jay Bruce and Derrick Robinson each had two hits for the Reds, who suffered their fourth consecutive setback and second straight walk-off loss. Cincinnati fell 1-0 to the Los Angeles Dodgers on Yasiel Puig's homer in the 11th inning Sunday.
The Reds came up empty after loading the bases with two outs in the first, but they were able to get on the board in the fifth.
After Robinson led off with a triple, Cesar Izturis hit a grounder to first and the speedy Robinson beat Alonso's throw home. Cincinnati wasted another bases-loaded opportunity later in the inning.
Chapman blew his fourth save of the season ... Reds reliever J.J. Hoover made his 15th consecutive scoreless appearance after retiring the Padres in order in the eighth ... Cincinnati was 0-for-5 with runners in scoring position.