Sweep gives Astros season series vs. Yankees, but Aaron Boone says 'it's not going to matter unless' it's October play Astros close out double-header sweep of Yankees (0:35) Matt Carpenter hits into a double play to give the Astros the win. (0:35) 11:47 PM ET ESPN News Services HOUSTON -- The Houston Astros opened the second half of the season by sweeping the New York Yankees in a doubleheader Thursday to inch closer in the standings to the team with baseball's best record. Yordan Alvarez and Alex Bregman both homered and combined for five RBI as the Astros completed the sweep with a 7-5 win in Game 2. Houston won the season series against New York, 5-2, with the Yankees' only leads throughout coming on walk-offs. They finished the season with a .151 team batting average against the Astros, their lowest single-season BA against a single opponent all time, according to ESPN Stats & Information. Yankees manager Aaron Boone seemed bothered by a question equating this season's results against the Astros to their struggles against them in the playoffs in recent year. Editor's Picks 1 Related "I understand it's a big story," he said. "I understand the season we're in. It's not going to matter unless (it's) October. If we happen to come back here in October we're going to show up. We're going to expect to win. We think we're really good. They're really good. Don't overstate this." The Yankees are 64-30. Houston is 61-32. "You want to get off to a good start, and I think everybody came in ready to play," Bregman said. "This is what we expect out of this ball club every single night ... and hopefully we can continue that for the second half." Rookie J.J. Matijevic 's pinch-hit RBI single with two outs in the ninth inning lifted the Astros to a 3-2 win in the opener of the day-night doubleheader. "This is huge for us to start out 2-0, to take our lead back to double digits," Houston manager Dusty Baker said of his team's lead over the Mariners in the AL West. Aaron Judge hit his MLB-leading 34th homer on a three-run shot off Brandon Bielak to the train tracks atop left field to cut the lead to 7-5 with one out in the ninth in Game 2. Rafael Montero , who pitched an inning in the first game, took over and was greeted with a single by Gleyber Torres . But Matt Carpenter grounded into a double play to end the game and give Montero his seventh save. Alvarez, who returned from the injured list Thursday, smacked his 27th homer to the seats in left field with two outs in the first to give Houston an early lead. The Astros went back-to-back when Bregman connected off Domingo Germán (0-1) four pitches later to make it 2-0. "The guy hasn't swung a bat against live pitching and hits it out on his first at-bat, he's pretty awesome," Baker said. "And Bregman is heating up." There were runners on second and third with two outs in the second when Alvarez doubled off the wall in left-center to score two more and extend the lead to 4-0. Bregman singled to left field to send Alvarez home and make it 5-0. Judge walked with one out in the third before the Yankees cut the lead to three on a home run by Torres. The doubleheader coming out of the All-Star break was scheduled to help make up a series that was postponed because of the lockout. Houston won the first game of the series on June 30. "It's definitely news to watch us play each other," New York's Giancarlo Stanton said. "But at the end of the day, we've got to stay ahead of them for home-field (advantage)." Germán allowed six hits and five runs in three innings in his season debut after missing the first half of the season with a shoulder injury. Houston starter Luis Garcia (8-5) yielded three hits and two runs in five innings for his fifth straight win after losing his previous four decisions. In Game 1, Bregman led off the Houston ninth with a single against Michael King (6-3). Bregman advanced to third on Aledmys Díaz's double. After Yuli Gurriel struck out, pinch-hitter Alvarez was walked intentionally to load the bases. King looked as if he might be able to escape the jam after he struck out McCormick, but Matijevic drove in Bregman with an infield single to shortstop. "The bullpen did a great job and boy, that was an exciting win for us and the fans and for J.J.," Baker said. "I was happy for J.J." The Astros carried a 2-1 lead into the ninth. But Aaron Hicks singled against Héctor Neris (3-3) and scored on Isiah Kiner-Falefa's two-out single, a grounder that rolled just past shortstop Jeremy Peña for the tying hit. DJ LeMahieu homered in the fifth, but the Yankees were just 1 for 8 with runners in scoring position. Jordan Montgomery tied a season high with eight strikeouts in 6 2/3 innings. He allowed seven hits and walked one. Cristian Javier tied a season high by issuing four walks while allowing one run and two hits in five innings. It was Javier's first start against the Yankees since he pitched seven innings in a combined no-hitter at New York on June 25. Neris and Ryan Pressly finished the historic gem. It was just the third doubleheader for the domed Minute Maid Park, which opened in 2000. Information from The Associated Press was used in this report.