HOUSTON -- What is serving as a winning formula for the surprising Houston Astros through the opening six weeks of the season -- abundant slugging and solid pitching -- played out to similar results Tuesday night.

Right-hander Roberto Hernandez took advantage of an early lead and recorded his fifth quality start, and the Astros held on for a 6-4 victory over the Oakland Athletics at Minute Maid Park.

Hernandez (2-3) worked six innings, allowing two runs on seven hits and two walks with three strikeouts. He pitched effectively while ahead, holding on to 2-0 and 3-1 leads to get the Astros (26-14) back on track following their loss to Oakland in the series opener Monday night.

The Astros bashed three more home runs to add to their major-league-leading total, which stands at 60. Left fielder Colby Rasmus provided critical insurance with a two-run shot to right field off Athletics left-hander Fernando Abad in the eighth. Two batters later, catcher Jason Castro cranked his fifth home run for a four-run lead.

First baseman Chris Carter hit a two-run shot in the second inning.

"I hope we do it for four more months," Astros manager A.J. Hinch said of the homers and strong pitching. "The whole night was set up by how we approached (Athletics right-hander) Sonny Gray. One of the best pitchers in our league, the first time we've seen him this season, but we were really locked in with a real disciplined approach of how to attack him. We got him up to 100 pitches in five innings."

Oakland (14-27) cut the deficit to one run on two occasions but couldn't get over the hump in support of Gray, who allowed three runs on seven hits and three walks with four strikeouts over five innings. Gray (4-2) exited with 104 pitches, and the Astros feasted on Abad.

The Athletics fashioned a threat in the ninth inning, scoring twice to chase Astros closer Luke Gregerson from the mound. However, Houston right-hander Pat Neshek struck out Oakland center fielder Billy Burns, who represented the tying run, on three pitches to earn his first save.

Oakland squandered an opportunity to strike first with two instances of overaggressive baserunning in the second inning.

First baseman Max Muncy was thrown out attempting to score from first on a one-out double by third baseman Brett Lawrie. On a subsequent infield single by center fielder Sam Fuld, Lawrie was erased trying to score from second.

"I didn't see how hard he was going into third," Oakland manager Bob Melvin said of Muncy. "If you're going hard from the very beginning, I guess there's a chance you could score."

The original call on Lawrie was reviewed for just under three minutes and upheld, and Houston struck in its next at-bat to take a lead for good.

Carter followed a leadoff double from Rasmus with a two-run blast to left off Gray, his seventh homer supplying Houston a 2-0 lead.

"He's just strong." Gray said of Carter. "He hit that ball with one arm, and it went a mile. I look back (and) it wasn't a bad pitch. It was 3-2 and I was challenging him earlier in the game, and he hit it a mile with one arm. I wouldn't change anything, just challenged him and he's a strong guy."

Oakland sliced the deficit in half when right fielder Josh Reddick doubled home shortstop Marcus Semien in the third. The Astros reclaimed their two-run lead on an RBI single by Gattis in the fifth inning.

"It's good to see us hit some home runs and score on Sonny," Gattis said. "To get the lead on him with (Carter's) home run was huge, then keeping it on him."

NOTES: Astros manager A.J. Hinch announced that RHP Lance McCullers will make a second career start Saturday against the Detroit Tigers. McCullers made his major league debut Monday night against the Athletics, allowing one run, three hits and three walks with five strikeouts in 4 2/3 innings. ... Athletics LHP Drew Pomeranz will return to Oakland on Wednesday for additional evaluation of his ailing left shoulder. Pomeranz departed his start Monday night with shoulder tightness in the middle of an at-bat in the fifth inning. There is a possibility that Pomeranz could land on the disabled list, depending upon the results of the examination. ... The Astros on Monday traded minor league LHP Chris Lee to the Baltimore Orioles in exchange for slots 46 and 76 for the 2014-15 international pool.