Pirates 3, Cardinals 1: Ike Davis homered for the second straight contest and Jeff Locke extended his unbeaten streak to five starts with 7 1/3 strong innings as host Pittsburgh won the three-game series with St. Louis.Andrew McCutchen returned to the lineup after leaving Tuesday's contest with rib discomfort and contributed a sacrifice fly for the Pirates, who are one game behind San Francisco for the National League's second wild-card spot. Locke (6-3) allowed one run and six hits while contributing a pair of singles and a run scored.Adam Wainwright (15-9, 2.59 ERA) lost consecutive decisions for the first time this season after yielding three runs and eight hits in six innings, and is 2-4 with a 5.17 ERA in his last six turns. Matt Holliday homered for wild card-leading St. Louis, which is two games behind Milwaukee in the NL Central.Wainwright was trying to become the majors' first 16-game winner, but Davis crushed the first pitch he saw over the wall in right-center in the second - a two-run shot that gave Pittsburgh a 2-0 lead. Holliday cut the deficit in half with a two-out blast to left in the third for his 13th homer of the season and first in 21 games.The Pirates restored their two-run advantage in the bottom half when Locke led off with a single and scored on McCutchen's sacrifice fly with the bases loaded and none out. Tony Watson recorded the final two outs in the eighth before Mark Melancon worked around a lead-off single in the ninth to earn his 24th save.GAME NOTEBOOK: Davis' home run - his 10th - landed in nearly the same spot of his pinch-hit three-run shot in the eighth inning Tuesday that gave Pittsburgh a 5-2 victory. ... Pirates RF Travis Snider departed after the third inning because of left hamstring discomfort while INF Pedro Alvarez did not play and was wearing a walking boot prior to the game after leaving Tuesday's contest with a sprained left foot. ... Pittsburgh, which has won five of its last seven contests and trails Milwaukee by 4 1/2 games, improved to 6-0-1 in its last seven home series against the Cardinals.