There were no first-day jitters for Astros right-hander Zack Greinke. His heartbeat was as calm as ever for six innings Thursday night at the Oakland Coliseum, where he carved up the A’s and collected his first career Opening Day win -- and the 209th win of his career -- in Houston’s 8-1 runaway victory.

Greinke threw at least six innings without allowing a run for the 65th time in his career, as the Astros got back-to-back homers from Michael Brantley and Alex Bregman to lead off the eighth inning and cruised to their club-record ninth consecutive Opening Day win. Houston hasn’t lost an Opening Day game since it moved to the American League in 2013.

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The Astros’ nine consecutive wins in openers ties the longest streak in the modern era (since 1900), joining the Mariners (2007-15), Reds (1983-91), Mets (1975-83) and St. Louis Browns (1937-45).

“I feel our team showed up in a great position in camp,” Bregman said. “Everyone worked extremely hard during the offseason. It was a good way to get off to a good start tonight. I thought we had good at-bats through the order and pitched really well. I thought it was an all-around team win.”

Greinke, who made his 460th career start (MLB's active leader) and his fifth on Opening Day, held the A’s to two doubles and a single, didn't issue a walk and struck out four. He faced one batter over the minimum, with a pair of double plays getting turned behind him.

With 2020 breakout left-hander Framber Valdez (fractured left ring finger) on the injured list and veteran right-hander Jake Odorizzi (late free-agent signing) not expected to join the rotation until later in the month, Greinke provides stability and reliability to the rotation.

“He threw some quality pitches, and he was kind of in midseason form,” Astros manager Dusty Baker said. “We were hoping he would go five, but indeed, he went six.”

In his first start of 2020, Greinke tired after only 58 pitches and 3 1/3 innings, saying afterward that his endurance wasn’t there. That wasn’t the case this year.

“He just kept us off-balance with the slider and mixed in that curveball, being able to put his heater on both sides of the plate,” A’s right fielder Chad Pinder said. “He’s Zack Greinke for a reason, and he pitched a great game.”

Greinke spread his arsenal around, throwing each of his four pitches at least a dozen times in his 82-pitch outing. His four-seam fastball (35 pitches) and changeup (20) accounted for 67 percent of his pitch selection. Greinke was pleased with his command of those offerings, but not as much with his slider, which was a point of emphasis in the spring.

“I felt like I was getting tired in the fourth, but all my pitches were good,” Greinke said. “I guess it was better than last year. Last year, when I got tired, my pitches kept getting worse. I kept my pitches sharp and located them good and felt good.”

The Astros, whose three-year reign in the AL West was snapped last season when the A's won the division (before Houston eliminated Oakland in the AL Division Series), took a 3-0 lead in the sixth on a two-run double by Yordan Alvarez. The 2019 AL Rookie of the Year Award winner, Alvarez returned to action after playing in only two games last year due to right knee surgery.

Alvarez had three RBIs, which was a great sign for the Astros, as was Brantley (3-for-4) and Bregman (2-for-4) setting the table from the Nos. 2 and 3 spots in the lineup.

“We’ve still got some improvement,” Baker said. “A few guys are trying to get their stroke. You always want to win the first one as a manager … get that first win under your belt.”