Off to the best start in franchise history, the Arizona Diamondbacks look to keep their perfect record intact this evening when they continue a three-game series with the San Diego Padres.

The defending National League West champions opened the season with a three- game sweep of the Giants, then improved to 4-0 for the first time in club history with Tuesday's 4-2 extra-inning victory over the Padres.

It looked like it might end up being a frustrating game for the Diamondbacks, who did nothing at the plate following Paul Goldschmidt's two-run double in the first inning until Chris Young followed Gerardo Parra's at-bat, in which the outfielder was hit by a pitch, with a home run into the left-field seats against former teammate Micah Owings.

In his Arizona debut, Trevor Cahill struggled with his command and walked six batters over six innings in addition to a run and two hits. Still, he was in line to get the win until Brad Ziegler allowed a triple to Orlando Hudson in the seventh and a run-scoring hit to Jason Bartlett.

"I was just happy to come out with as little damage as possible," Cahill said.

San Diego, which salvaged the finale of a four-game series with the Dodgers on Sunday, got a solid outing from starter Edinson Volquez, who gave up two runs over seven innings with eight strikeouts.

"Nice solid three-pitch mix. Threw the ball very well," San Diego manager Bud Black said of Volquez.

The Diamondbacks look for a 5-0 start tonight behind Joe Saunders in the left- hander's first start of the season. Saunders, who is tied for fourth among southpaws in wins since 2008, went 12-13 with a 3.69 earned run average a season ago, setting a career high with 212 innings and matching a personal best with 33 starts.

Saunders, 30, is 5-3 with a 3.00 ERA in his career versus the Padres, who he dominated a season ago. He went 3-1 with a 1.47 ERA against them in 2011, winning the last three starts while giving up only one run in 24 2/3 innings.

While Saunders will be making his season debut, Cory Luebke makes his second start for the Padres after struggling in his first go around.

The 26-year-old lefty took a loss versus the Dodgers on Friday, allowing a career high-tying six runs -- five earned -- and nine hits over 4 2/3 innings.

Luebke has made three previous starts against Arizona and has lost all three, giving up nine runs in 17 innings for a 4.76 ERA. He also received just three runs of support in that time.

The Padres won three of their final four games versus the Diamondbacks last year, but Arizona still won the season series 11-7.