Hundley, in his second major league season, stood just outside the batter's box after he hit the ball and flipped his bat as the 0-1 pitch from Micah Owings (3-4) landed into the left-field seats, an estimated 421 feet away.

"I was just trying to enjoy the moment," Hundley said. "That was special."

Hundley's homer, his second of the season, landed in the second deck to end the 5-hour, 14-minute game, the longest of the season in terms of time and innings for both teams.

"Toward the end, I was getting a little tired," said Owings, who threw a hanging slider. "I'm not going to make any excuses. I was ready."

Owings, the Reds' fifth starter, was pitching out of the bullpen because the Reds are short-handed since Nick Masset was not available due to a strained left oblique. The right-hander was told he would need to be ready in case of emergency for both Friday and Saturday's games.

Owings allowed one run on three hits in 5 2/3 innings.

"[Owings] was out of gas but we didn't have much choice," Cincinnati manager Dusty Baker said.

Closer Francisco Cordero was the Reds' final reliever left in the bullpen.

The win was San Diego's second straight after losing six in a row and 19 of 23. The Padres are 4-2 in extra innings games while Cincinnati is 0-3.

"They taste a lot better when you win," San Diego manager Bud Black said.

Rookie Luis Perdomo (1-0), the Padres' eighth pitcher, pitched three hitless innings for the first win of his major league career.

San Diego's seven relievers combined to throw 10 1/3 innings of scoreless relief, allowing three hits with eight strikeouts and five walks.

"The bullpen was unbelievable," Hundley said. "They threw strike one, got ahead. They all came through. They kept us in the game.

The Padres stranded 17 runners compared to nine for Cincinnati. San Diego twice had the bases loaded in the extra innings.

The previous longest game by innings this season came earlier this month, when Seattle and Oakland went 15 innings.

Last Memorial Day weekend, the Padres beat the Reds 12-9 in 18 innings in San Diego when Adrian Gonzalez hit a three-run homer off Edinson Volquez, Saturday night's starter.

The Padres scored twice in the eighth inning to tie the score at 5-all.

Gonzalez led off with a walk off against Arthur Rhodes. David Weathers replaced Rhodes and gave up a double to Scott Hairston before Jody Gerut grounded out to bring in Gonzalez. Weathers then walked two batters, sandwiched around an out, to load the bases.

Weathers walked pinch-hitter Drew Macias on a full count to bring in the tying run. Weathers thought he had Macias struck out earlier in the at-bat on a pitch close to the inside corner. The veteran reliever was visibly upset with home plate umpire Jim Joyce and the two exchanged words when Weathers was pulled.

Daniel Ray Herrerra relieved Weathers and retired Brian Giles to end the inning.

Laynce Nix and Jay Bruce each hit two-run homers for Cincinnati, which pulled Volquez in the sixth inning with mild back spasms.

Nix connected in the fifth inning of Josh Greer to give the Reds a 3-2 lead and Bruce hit his 11th homer one inning later off Josh Geer.

Volquez allowed two runs in the first inning, including Giles' leadoff homer, before he settled down.

The right-hander was cruising with two outs in the sixth inning before he walked Kevin Kouzmanoff. He ran the count to 3-0 on Hundley when he went behind the mound and appeared to be trying to stretch his back. He came out of the game before throwing another pitch with mild back spasms.

Volquez allowed two runs on four hits with three walks and two strikeouts.

Game notes
Giles' leadoff homer was the fourth of his career. The other three all came in 2007, the last on Sept. 30. ... Weathers was credited with a blown save making the Reds the last team in the majors to register a blown save for the second year in a row. ... Rhodes allowed an earned run, making Padres closer Heath Bell the only NL qualifying reliever who has not allowed an earned run. ... Padres RHP Greg Burke made his major league debut with one inning of scoreless relief.