SAN DIEGO — Newcomer Pedro Ciriaco tripled in the go-ahead run in the seventh inning and hit a two-run homer in the eighth to lead the San Diego Padres to a 6-3 victory against the Los Angeles Dodgers on Thursday night.

The Padres, who had three terrific defensive plays, won for the eighth time in 10 games and popped above .500 for the second time this season.

Dodgers rookie Yasiel Puig homered on his first swing at Petco Park, giving him six overall and three against the Padres since his big league debut on June 3.

The Dodgers, who've been in last place in the NL West since May 6, have lost eight of 11.

It was L.A.'s first visit to Petco Park since the teams brawled on April 11 after Zack Greinke hit Padres slugger Carlos Quentin with a pitch. Quentin rushed the mound and slammed into Greinke, breaking the pitcher's left collarbone. Greinke is scheduled to start Saturday night.

The Padres had impressive catches against consecutive batters in the seventh. Retreating second baseman Logan Forsythe made a sprawling catch of Mark Ellis' blooper and left fielder Chris Denorfia tumbled over the low wall along the line to catch a foul ball by pinch-hitter Elian Herrera.

In the eighth, Padres center fielder Alex Amarista made a great diving catch of Juan Uribe's sinking liner.

Ciriaco, acquired from the Boston Red Sox last Friday, capped his big night with a homer to left off Peter Moylan with one out in the eighth for a 6-2 lead. It was his first with the Padres and second overall.

In the seventh, Ciriaco tripled into the gap in left-center to bring in Grandal, who reached on a leadoff, opposite-field double down the left-field line. The ball got caught behind padding on the fence and Grandal had to hold up at second.

Matt Guerrier (2-3) opened the inning in relief of starter Stephen Fife and allowed the extra-base hits to Grandal and Ciriaco before making way for Paco Rodriguez.

After Forsythe walked, Ciriaco was thrown out at home when first baseman Adrian Gonzalez raced in, scooped up Will Venable's bunt and threw to catcher A.J. Ellis for the tag. Chase Headley, who struck out in his first three at-bats, singled up the middle to bring in Forsythe.

Nick Vincent (2-0) pitched the seventh for the win.

Puig, a 22-year-old Cuban defector, drove a fastball from Jason Marquis an estimated 406 feet into the sandy play area beyond the fence in right-center with one out in the first in his 58th big league at-bat.

Marquis was much more careful against Puig after that, striking out the phenom his next two times up.

Puig made his big league debut June 3 against the Padres, hitting two singles and making a strong throw from right field to first to complete a game-ending double play in a 2-1 Dodgers victory.

The next night, he hit two homers and drove in five runs as the Dodgers rallied to beat the Padres 9-7.

San Diego went ahead 2-1 in the fifth on consecutive RBI singles by Marquis and Forsythe. One run was unearned because of second baseman Mark Ellis' fielding error.

L.A. tied it in the sixth when Uribe's sacrifice fly brought in Hanley Ramirez.

A.J. Ellis homered off Huston Street in the ninth, his third.

Both starters went six innings.

Marquis, trying for his 10th victory, allowed two runs and seven hits, struck out five and walked one. Fife allowed two runs, one earned, and four hits, struck out six and walked one.

NOTES: The Dodgers arrived in San Diego at about 3:30 a.m. after splitting a day-night doubleheader at Yankee Stadium on Wednesday. They did not take batting practice. ... Quentin, San Diego's LF, missed his sixth consecutive game with a sore shoulder. ... San Diego 1B Yonder Alonso will visit a hand specialist Monday to examine his broken right hand. Alonso has missed 14 games since suffering the injury last month. He's not expected back before the end of the month. ... Dodgers OF Scott Van Slyke (left shoulder bursitis) will begin a rehab assignment Friday at Albuquerque.