OAKLAND, Calif. -- Houston Astros All-Star Kyle Tucker has been one of the American League's best hitters against left-handers this season. He credits his success to hours of playing Wiffle Ball with his older brother, Preston, when the two major leaguers were growing up.

Tucker hit three home runs in a game for the first time in his career and drove in four runs, Alex Bregman also went deep and the Astros beat the Oakland Athletics 6-4 on Friday night.

The performance raised Tucker's average against lefties to .364 (43-for-118) with seven home runs.

"That's a big part of just playing Wiffle Ball in the backyard with my brother being a lefty," Tucker said. "He's probably helped out with the comfortability for facing guys like that."

Preston Tucker is a left-handed pitcher who is currently on the injured list with the San Diego Padres.

Kyle Tucker improved on his success against lefties from the outset Friday. The 26-year-old right fielder hit a solo homer off A's starter JP Sears in the first inning that extended his road hitting streak to 18 games. Tucker hit a two-run shot off Sears in the fifth inning and added a solo homer into the right field stands off Tayler Scott in the seventh for his 17th of the season.

According to ESPN Stats & Information research, it makes him just the third Astros player ever with a three-homer game over the past 15 seasons, joining Yordan Alvarez and George Springer. It also was the fifth multi-homer game of Tucker's career, including the playoffs.

"They were three home runs that we really needed," Astros manager Dusty Baker said. "Especially that last one, it gave us some breathing room because they were right on our tails. Can't get much more locked in than that."

The win moved the Astros (55-43) 12 games over .500, matching their season high.

Houston's Framber Valdez (8-6), who left his last start due to a left calf cramp, pitched five uneven innings and beat Oakland for the third time this season. The 29-year-old left-hander allowed six hits and four runs with four strikeouts and two walks, helping the Astros win their ninth straight against Oakland in a streak that is dated to last season.

Ryan Pressly, the fifth Astros reliever used by Baker who was pitching in his third straight game, recorded the final three outs for his 23rd save this season and the 100th of his career.

"I never thought I'd get here to be honest with you, so for me it is special," Pressly said.

Tony Kemp had two hits, was hit by a pitch and scored twice for the MLB-worst A's (27-73). Oakland has lost 10 of 12 overall.

The only pitcher to remain in Oakland's rotation all season, Sears allowed eight hits and five runs in 5⅔ innings. Sears is winless since June 11.

"Other than Kyle Tucker, I thought it was great," A"s manager Mark Kotsay said. "Overall, he took over the game tonight. JP still gave us a chance to win the game when he walked off the mound."

The Associated Press contributed to this report.