Los Angeles, CA (SportsNetwork.com) - Justin Upton hit a grand slam and finished with six RBI to lead the San Diego Padres in an 11-3 victory over the Los Angeles Dodgers in the finale of a three-game set.

Derek Norris drove in a pair of runs, while Will Venable was 4-for-5 with three runs scored for the Padres, who snapped a four-game losing streak that saw the team score just three runs over that span.

"I'm feeling pretty good and getting the barrel to the ball more often," said Upton. "It was nice to get some runs in the situations today. We were patient today."

James Shields (6-0) stayed undefeated on the season after giving up three runs on five hits with a walk and seven strikeouts in seven innings. He has struck out at least seven batters in each of his last six starts, and nine of his 10 starts this season.

"We did a great job of scoring runs early," said Shields. "I threw a lot of fastballs and mixes my pitches pretty well. Upton has put us on his back, he's been phenomenal."

Alex Guerrero hit a two-run homer for the Dodgers, who have lost four of their last six. Carlos Frias (3-2) was clobbered for 10 runs on 12 hits in just four-plus innings on the mound.

"Carlos threw a lot of balls over the middle of the plate," said Dodgers manager Don Mattingly. "It looked like he had trouble throwing strikes with his fastball. Today he couldn't recover."

San Diego's first three batters reached base to start the game, and Upton cleared them with a grand slam, his 12th homer of the season, for a 4-0 lead.

The Padres kept pouring it on in the second as Upton doubled home two more runs with the bases loaded, and Norris followed with a two-run single to extend the lead to 8-0.

Will Middlebrooks led off the third with his fifth homer of the season, and a sacrifice fly from Alexi Amarista in the fifth made it a 10-0 game.

The Dodgers finally got on the board in the seventh as a run came home after Andre Ethier hit into a double play, and Guerrero followed with a two-run homer to make it a 10-3 game.

Abraham Almonte's RBI single in the eighth accounted for the final score.

Game Notes

The Padres stay in the area to play the Angels for three games starting on Monday ... The Dodgers host the Braves for a three-game set beginning Monday ... The Padres, who finished the game with 20 hits, went 7-for-13 with runners in scoring position ... It was the fourth grand slam for Upton in his career, three of which have come against the Dodgers.