St. Louis looks for its 15th victory in 18 games and its 10th straight win with Pineiro on the mound Wednesday night against the Houston Astros at Busch Stadium.Wainwright pitched eight innings of three-hit ball in Tuesday's 1-0 win over the Astros to help the Cardinals (73-54) improve to 14-3 since Aug. 7 and move nine games ahead of the free-falling Chicago Cubs. Albert Pujols provided Wainwright with all the offense he needed with a run-scoring double in the first inning, his 107th RBI of the season.With the victory, Wainwright became the NL's first 15-game winner, moving ahead of Carpenter (14-3).Led by Wainwright, Carpenter and Pineiro (12-9, 3.15 ERA), St. Louis boasts a formidable rotation that figures to be tough to beat for a possible best-of-five first-round playoff series. The Cardinals are 27-3 in games started by those three since July 3."The whole rotation, we just keep going out there and feeding off each other," Wainwright said.While Wainwright and Carpenter are among the NL leaders in victories, the Cardinals have been at their best with Pineiro on the mound.St. Louis has won each of Pineiro's last nine starts with the right-hander going 6-0 with a 2.70 ERA in that stretch. He hasn't lost since June 28 against Minnesota.Pineiro is coming off a very strong outing, allowing one run and four hits with seven strikeouts in 7 2/3 innings of Thursday's 5-1 win over San Diego. He has posted a 2.95 ERA in winning his last three starts and hasn't won four in a row since April 10-27, his first four outings of the season.That streak began against the Astros, his only appearance of the season against them. Pineiro allowed two runs and eight hits 6 2/3 innings of a 5-3 win over Houston in April and has a 2.97 ERA in five career starts against the Astros, but is 2/3 in those games.Houston (61-64), which has lost two straight after winning four in a row, counters with Roy Oswalt (7-4, 3.83).After yielding 11 runs in 11 innings in his first two starts after missing nearly two weeks due to a lower back strain, Oswalt bounced back by allowing three hits with no walks in seven innings of a 1-0 win over Arizona on Friday.Building on that performance won't be easy for Oswalt, who is 0-1 with a 6.23 ERA in two starts against the Cardinals this season. The right-hander is 0-2 with a 5.68 ERA in his last three starts at Busch Stadium after going 1-0 with a 0.42 ERA in his first three there.Like Oswalt, the Astros' offense hasn't had much luck in St. Louis.Houston has scored three runs or fewer in its last nine games at Busch Stadium, winning once in that span.The Astros, who opened a nine-game road trip Tuesday, dropped to 4-13 away from Houston since July 18 with Tuesday's defeat.