PHOENIX -- San Diego left fielder Justin Upton loves hitting at Chase Field, where he has 70 career home runs. He also appears to love picking on the team that plays there.

Upton's leadoff homer in the 12th inning broke a tie and lifted the Padres to a 6-4, 12-inning victory over the Arizona Diamondbacks on Saturday night.

It was Upton's sixth homer in 18 career games against his former team and his second game-winner this season.

"It's old hat," Upton said of facing Arizona, where he spent his first six seasons. "I'm just trying to cheer on my teammates, play the game. I'm just having fun, going out and playing the game."

Second baseman Alexi Amarista singled in an insurance run in the 12th for the Padres (17-15), who have won two straight and six of nine.

"Justin showed why he is who he is and why he gets paid," Arizona manager Chip Hale said.

First baseman Wil Myers had three hits, two doubles and two runs, Upton contributed two hits and two RBIs and catcher Derek Norris added two hits and an RBI for the Padres.

Upton connected on a 3-2 fastball from right-hander Randall Delgado (1-2), the same pitch he hit in the eighth inning to beat Delgado and the Diamondbacks 3-2 in San Diego on April 15.

"It's danger," San Diego manager Bud Black said of Upton's at-bats. "Raw power. It's dangerous. I know all the years that I pitched, those types of players, in a close game, heads up. One pitch, one mistake, and it's a quick point."

San Diego right-hander Kevin Quackenbush (1-0) pitched two innings of relief to pick up the victory

Arizona rallied with two outs to tie the score in the ninth against San Diego closer Craig Kimbrel. Pinch-hitter Danny Dorn tied it at 4 with a two-run double after catcher Jordan Pacheco walked and pinch-hitter Aaron Hill singled. Dorn hit a 98 mph fastball.

Dorn, who played 939 minor league games in 10 seasons before having his contract purchased April 12, had his first two major league RBIs and broke Kimbrel's streak of consecutive save conversions at 35, 10 this season.

"His stuff is unbelievable," Dorn said. "One of the best pitchers, and I just tried to stay short and give my team a chance. Luckily, it was down, so I was able to drop the barrel on it a little bit."

"It happens to the best of them," Black said of Kimbrel's inning.

Left fielder David Peralta had two hits and an RBI for the Diamondbacks (13-16), who have lost two in a row.

Arizona first baseman Paul Goldschmidt had a single and four walks. Goldschmidt was hitting .352 and was tied for second in the league in RBIs and third in the league in homers entering the game.

The Diamondbacks had runners on first and third with one out in the 10th before shortstop Cliff Pennington lined to second baseman Jedd Gyorko, who was playing in. Gyorko dived to his left to make the catch and start a double play.

"I didn't have a whole lot of time to react," Gyorko said. "I just dove, hoping to try to know it down as well as I could. Fortunately enough, (the ball) went right in my glove."

Arizona right fielder Ender Inciarte singled against Quackenbush with one out in the 12th and took second on defensive indifference before Goldschmidt struck out to end the game.

San Diego right-hander Tyson Ross gave up two runs and five hits in six innings.

Arizona right-hander Chase Anderson gave up one run and five hits in seven innings, striking out two and walking two. He did not get a decision when the bullpen could not hold a 2-1 lead.

NOTES: OF Abraham Almonte grounded out as a pinch-hitter after being recalled from Triple-A El Paso after 1B Yonder Alonso (bruised scapula) was officially placed on the disabled list Saturday. Almonte, 25, was hitting .308 with four homers, 17 RBIs and four stolen bases in 26 games for El Paso. ... The Diamondbacks have not announced a Sunday starter but are likely to turn to a bullpen arm, manager Chip Hale said. RHP Daniel Hudson appears the most likely candidate, because he has not pitched since going one inning Thursday. Because of rainouts Monday and Tuesday in Colorado, Arizona has no starting pitcher on either the 25-man or the 40-man rosters available on normal rest. ... Arizona optioned 1B/OF Danny Dorn to Triple-A Reno after the game and will announce a corresponding move Sunday. ... Arizona 1B Paul Goldschmidt had reached base via hit or walk in 21 straight games against San Diego after walking in the first inning Saturday.