OAKLAND -- Given the 9.64 ERA that Hogan Harris compiled over his previous four outings, an unfavorable outlook heading into Thursday’s matchup against the defending World Series champion Astros would have been justified.

While the end result was a 3-1 A’s loss to Houston at the Coliseum, it was a defeat that came despite Harris turning in one of his better performances of the season. The rookie left-hander limited Houston to two runs on four hits and no walks with six strikeouts in six innings, producing the second quality start of his young career.

Chas McCormick’s two-out single in the second was the only hit allowed by Harris in his first five scoreless innings, as he retired 17 of his first 18 batters faced. The brunt of damage against him came in the sixth, when the top of Houston’s lineup strung together two runs on a trio of two-out hits, all of which came while Harris was ahead in the count.

“Hogan did a great job today,” A’s manager Mark Kotsay said. “There in the sixth inning with two outs, to give up three two-out hits, it happened quick. Unfortunately, he wasn’t able to execute. He had both guys [ahead in the count] and ended up giving up two hits and then [Kyle] Tucker comes up and hits the ball in the gap. Really, that inning was the storyline of the night.”

Even on a night that saw him rack up six strikeouts and a career-high 16 whiffs, it was the zero walks that brought Harris the most satisfaction. In his four outings prior, he had issued 13 walks and hit two batters over 18 2/3 innings, straying away from what led to his success earlier in the season.

On Thursday, Harris fired 58 of his 74 pitches for strikes. It was that regained penchant for consistently attacking the zone that played a large part in what finished as a speedy two-hour, 12-minute contest.

“Their young pitcher had excellent command of his fastball and a real good command of his changeup,” Astros manager Dusty Baker said of Harris. “And so, boy, it was in the fifth inning before we knew it.”

Harris attributed the bounceback performance to a couple of mechanical adjustments that he discovered over the recent rough stretch of outings. After going over video in meetings with A’s pitching coach Scott Emerson and assistant pitching coach Mike McCarthy, the three noticed that Harris had been spraying the ball around as a result of dragging his arm across his body on the follow-through. Against Houston, Harris found a more compact delivery again, and success followed.

“The whole time where I was having the walks the last few outings, it seemed like every walk that I had scored,” Harris said. “It felt good to finally get those couple of mechanical things honed in that I really need to. Once it clicked, it just felt natural again. It’s just tough to get back to that point once you lose it. But we were able to find it fairly quickly. … I was really happy with the outing.”

A large focus of this second half for the A’s is seeing the development of its many young pitchers. On Thursday, it showed with Harris and continued with No. 5 prospect Freddy Tarnok, who took over in the seventh and finished the game with three solid innings of one-run ball.

Making his second appearance of the season after missing the first half due to a right shoulder strain, Tarnok averaged 95.2 mph with his fastball over the 51-pitch outing and maxed out at 97 mph. Walking two batters and striking out one, his lone hit allowed was costly, as Alex Bregman turned on a 3-2 fastball left over the zone for a solo homer in the ninth.

“He looked good,” Kotsay said of Tarnok. “He can beat hitters with his fastball. Bregman got the head out on a 3-2 heater there in the ninth. Overall, he’s coming along. … It was good to see him get his pitch count back up a little bit. The curveball is going to be a pitch for him that he needs to land. That will increase his success.”