Alexi Amarista had a two-run homer plus two doubles, reserve catcher John Baker drove in his first two runs of the season to open the scoring and Jason Marquis picked up his fourth straight win Wednesday afternoon at the Padres defeated Baltimore 8-4 to complete a two-game sweep of the Orioles at Camden Yards. The two wins followed three losses last weekend at Tampa Bay, giving the Padres a 2-3 record on a five-game interleague trip against American League East contenders. The Padres open a seven-game homestand at Petco Park Thursday night against the Washington Nationals and former San Diego State pitcher Stephen Strasburg. In addition to going 3-for-4 with three runs scored plus the two RBIs, Amarista made a running catch in right-center in the seventh to help keep the Orioles at bay. Marquis came out the winner over Freddy Garcia in a match of two right-handers who battled during spring training for a spot in the Padres rotation. Marquis, who improved to 5-2 with a 3.49 earned run average, allowed two runs on seven hits and four walks over five-plus innings. Garcia, who signed a contract with the Orioles after being cut by the Padres near the end of spring training, allowed four runs on seven hits and two walks in 3 2/3 innings in his third start for Baltimore. The Padres scored two runs in the top of the second and fourth innings against Garcia and the Orioles answered with a solo homer in the bottom of both innings against Marquis. Baker, who hadn’t had a hit in 19 at-bats since having three hits on April 7, gave the Padres a 2-0 lead with a two-run, two-out single in the second.