Jeff Samardzija held the Padres to two runs over eight innings, and Kevin Pillar, Evan Longoria and Austin Slater homered to lead a 14-hit Giants attack as San Francisco opened a three-game series in San Diego with a 13-2 rout on Monday night.

Pillar's three-run homer off reliever Robert Stock capped the Giants' scoring. Longoria, Slater, Tyler Austin and Buster Posey all drove in two runs for the Giants while Donovan Solano, Posey, Longoria, Slater and Joe Panik had two hits apiece.

Samardzija (5-7) didn't allow a hit until Franmil Reyes singled with two outs in the fourth, and the Giants were leading 7-0 when the Padres finally scored in the sixth. Samardzija gave up five hits and two walks while striking out six.

After allowing only two runs over 13 innings in his first two major league starts, Padres left-hander Logan Allen gave up six runs on seven hits and two walks with three strikeouts in four-plus innings. Allen (2-1) took his first big-league loss.

The Giants scored their first two runs in the fourth -- thanks to a leadoff walk drawn by Austin, an RBI double by Longoria and a run-scoring triple by Slater -- before breaking the game open with four runs in the fifth.

Samardzija triggered the big rally with a leadoff double. Austin drove in the first two runs with a bases-loaded double ahead of a two-run double by Posey.

Longoria and Slater, who was making his major league season debut, hit solo homers in the seventh off Padres reliever Phil Maton.

The Giants scored their final four runs in the eighth. Solano opened the inning with a double, moved to third on a flyout and scored on a wild pitch. Pillar's three-run homer off Stock followed a single and a hit batter.

Derek Holland pitched a hitless bottom of the ninth to close out the game.

The Padres and Giants are now 5-5 in their season series, with San Francisco having won the past three meetings.

--Field Level Media