HOUSTON -- Oakland Athletics manager Bob Melvin needed a postgame alert to grasp the personal significance of the grand slam third baseman Ryon Healy belted in the sixth inning.

But Melvin had an inkling of its gravity thanks in large part to the forceful hand slap Healy delivered when he returned to the visiting dugout.

Healy hit his first career grand slam to snap a tie and lead the Oakland Athletics to a 6-4 victory over the Houston Astros on Tuesday night at Minute Maid Park.

Healy smacked his 18th home run the opposite way to right field off Astros right-hander James Hoyt, who entered with two outs in a 1-1 game in relief of Houston starter Mike Fiers (5-3). Healy ran the count full before his drive plated Matt Joyce, Jed Lowrie and Yonder Alonso, whose two-out walk chased Fiers.

"I knew he was just going to slider the heck out of me so it was really just trying to get a pitch up in my zone," Healy said of Hoyt. "Fortunately, it took about 7-8 pitches and I finally got one and I didn't miss it."

Said Hoyt: "At the end of the day, I let the team down. I take full responsibility for that. They put me out there in a big time of the game, and I didn't do my job."

Athletics left-hander Sean Manaea (7-4) notched his first career win in seven starts against the Astros (52-26) by continually sidestepping danger. He allowed nine hits and three walks over 5 2/3 innings, yet Houston managed only one run.

"The first six innings are really the story of the opportunity (missed)," Astros manager A.J. Hinch said. "I think we left nine or 10 guys on base in those innings alone.

"We did a great job of getting guys on base, getting guys in scoring position, having that two-out at-bat, and we really couldn't win any of those at-bats."

Oakland (35-42) stretched its winning streak to four games -- all on the road.

The Astros rallied in the ninth against Athletics reliever Liam Hendriks, with George Springer drilling an opposite-field, three-run homer -- his 23rd -- to chase Hendriks and summon Oakland closer Santiago Casilla.

Casilla inducing a pop up from pinch-hitter Josh Reddick and a game-ending double play by Brian McCann after Jose Altuve and Carlos Correa greeted Casilla with consecutive hits.

Houston finished 1-for-10 with runners in scoring position and stranded 10.

Squandered opportunities proved detrimental to the Astros early, with Manaea stranding six baserunners -- all in scoring position -- through the fourth inning.

Complicating matters were the decisions of third base coach Gary Pettis to hold Correa and Marwin Gonzalez at third base following two-out doubles from Evan Gattis and Jake Marisnick in the first and second innings. Both calls were prudent, but when the Astros continually failed to cash in on scoring opportunities, those calls resonated.

It wasn't until the fifth that Houston tied the game, but even that frame came with a measure of frustration. The Astros loaded the bases with no outs only for Gattis to hit into a double play that scored Springer. McCann followed with a ground out as the Astros stranded a seventh baserunner in scoring position.

"It was one of those times where you had to battle through it and just try to get out as much as you can," Manaea said. "Overall I was pretty happy with everything but hopefully next time will be a little better."

NOTES: Astros RHP Collin McHugh will make a rehab start Friday with Double-A Corpus Christi. McHugh, on the 60-day disabled list with a right elbow impingement, opened the season on the 10-day DL after right shoulder tendinitis sidelined him during spring training. The elbow injury occurred during a rehab start with Triple-A Fresno on April 6. ... Athletics RHP Chris Bassitt will work one inning for High-A Stockton on Wednesday. Bassitt is making a return from Tommy John surgery performed May 6, 2016. He made two starts for Triple-A Nashville last month before being shut down following a setback. ... Astros RHP Brad Peacock was reinstated from the paternity list. His wife, Stephanie, gave birth to their first child, Colton Joseph, on Saturday. Peacock takes the roster spot of RHP Jordan Jankowski, who was optioned to Triple-A Fresno on Sunday.