In a game of squandered opportunities Sean O'Sullivan and the Padres didn't waste as many openings as their visitors.

They also didn't create as many which should have proved enough for the Reds in a low-scoring affair.

Then in one swing that all went out the door.

Pinch-hitting in the bottom of the ninth Chris Denorfia launched a first-pitch 98-mph heater from Cincinnati closer Aroldis Chapman over the centerfield fence for a 2-1 Padres victory Monday at Petco Park. The two-run shot was Denorfia's first career walk-off homer.

"Eighty percent of the time" said Bud Black "you know the sound of a home run. That sounded great off the bat."

The Padres manager said that before the game he and Denorfia had discussed just such a scenario.

"I told him to be ready for the guy at the end" Black said.

Denorfia apparently had steeled himself accordingly. All nine of his long balls this season have come against left-handed pitchers.

"Buddy's a great communicator" Denorfia said. "The way the lineup turned over I knew I was gonna face Chapman."

Before Denorfia's resounding blast San Diego had not had a hit since the third inning.

Thus the Padres continued their recent run in this the opener of an eight-game homestand on the heels of a fruitful road trip. They have won eight of their last 12.