OAKLAND -- After hitting a grand slam to highlight the Astros’ 9-1 victory Tuesday night over the Oakland A’s, Houston’s Alex Bregman insisted on slamming himself for what he has considered a subpar performance so far.

Bregman’s homer capped a five-run fourth inning that essentially clinched the Astros’ 10th consecutive triumph, marking the fourth time in the last five seasons that they’ve extended a winning streak into double figures. Houston matched its franchise record with 12 wins in a row from June 6-18, 2018, after capturing 11 straight games in 2017 and 10 in succession in 2015.

“The only thing better than a 10-game winning streak,” Bregman said, “is an 11-game winning streak.”

The Astros’ success has sustained Bregman’s spirit through what he considers an offensive lull.

Though the third baseman has a slash line of .302/.397/.472 that would leave most hitters envious, he believes he’s not making enough authoritative contact with fastballs.

“I’m hitting the softest .300 in baseball,” said Bregman, the Most Valuable Player of last year’s All-Star Game. “... I think I’ve just been terrible, honestly. I haven’t been good at all offensively. Today was a step in the right direction. … I’m getting beat by heaters that I never get beat by. Basically [I’m] just horrible at the plate. Honest, I’ve been terrible.”

But, Bregman summarized, “The one thing that I like is the win column. I’m glad that we’re winning games. That’s the most important thing.”

Bregman’s second career grand slam, which he delivered off A’s reliever Liam Hendriks, topped Houston’s shower of power that began with George Springer’s homer off the second-deck facade in left field. Former A’s mainstay Josh Reddick contributed a second-inning, two-run homer against A’s starter Marco Estrada (0-2)..

Reddick also singled in the fourth inning, improving his career batting average against Estrada to .545 (6-for-11) with three homers and six RBIs. Reddick’s team-high three hits lifted his batting average to .319.

“We’ve always said he’s a good hitter first; and the power will be there for him,” Houston manager AJ Hinch said.

That provided Houston starter Collin McHugh (3-1) with sufficient support. The right-hander allowed two hits in six innings as he lengthened his personal winning streak against Oakland to eight games, dating back to 2015. McHugh also lowered his ERA to 1.96 while striking out five, which hiked his season total to 27 in 23 innings.

“The guy is a pretty good pitcher,” A’s manager Bob Melvin said. “You look at their staff and last year he was pitching out of the bullpen with the same stuff he has right now. You look at our numbers across the board against him and around the league; he’s just pretty good. He keeps you off balance and throws very few fastballs in counts where you expect them. He’s tough to think along with and when he’s locating and getting ahead, it’s tough to string hits together.

“We do our fair share of damage here at home. You have to give [McHugh] credit. He pitched a really good game.”