HOUSTON -- Miles Mikolas threw six solid innings Wednesday afternoon, and then the Cardinals were able to turn it over to their bullpen for a win they needed to finish off their nine-game road trip.

Miles Mikolas surrendered two runs on five hits with three strikeouts and got just enough run support as St. Louis beat the Astros 4-2 at Minute Maid Park.

Mikolas pointed to getting ahead in the count as one of the keys to his success.

“There are a lot of aggressive swings on that team, so trying to use that against them,” he said. “Make a quality pitch early in the at-bat and try to get quick outs.”

He has allowed three runs or fewer in five straight starts. Wednesday marked his team-leading seventh quality start of the season.

“He’s been commanding the baseball really well,” St. Louis manager Oliver Marmol said. “He’s been at the bottom [of the zone] a lot more. His mix has been good. He’s made some small adjustments, but for the most part, he’s just in control of every at-bat. There’s a purpose behind what he’s throwing. It’s looked really good.”

Mikolas got mostly weak contact on the day. Houston had three hard hit balls off the right-hander, characterized by any ball with an exit velocity over 95 mph.

The two home runs hit by Trey Cabbage and Yainer Diaz had exit velocities of 106.9 mph and 97.3 mph, respectively, and a flyout by Yordan Alvarez in the first had an exit velocity of 100.8 mph.

Mikolas said he was happy with his approach against the Houston hitters.

“Me and [catcher Pedro] Pagés were on the same page most of the game,” he said. “We talked before the game, and we’re doing our scouting work and going over the guys and we went in with a really good plan. The important part is that we executed.”

Mikolas relied mostly on his sinker, which he threw 28 times out of 62 total pitches. He also threw 14 sliders and 11 four-seam fastballs.

“I was running that sinker,” Mikolas said. “They like to swing a lot, so pitches in off the plate are hard to hit. It’s a good spot for these guys. I kind of just tried to stay there as much as I could.”

Marmol said Mikolas was aggressive on the inside part of the plate.

“That’s important for him to have success, and he’s been able to command it a lot better.”

Mikolas got nine outs in the air and five groundouts as he let his defense work for him.

“To be able to do what he did today, he mixed everything,” Marmol said. “He got ahead of guys. A lot of soft contact. He gave us six, which is what we needed with our ‘pen being where it’s at.”

After Mikolas’ six innings, Marmol went to JoJo Romero and Andrew Kittredge for an inning each before Ryan Helsley threw a hitless and scoreless ninth for his MLB-leading 20th save of the season.

“We got three guys who are really good on the back end,” Marmol said of going to the bullpen despite Mikolas being at 62 pitches. “[Mikolas] was going right through the lane. At that point, it’s not pitch count. It’s more familiarity with the hitters that got him and the guys that were coming up had two homers against him. That’s JoJo’s lane there with two lefties coming up.”

Michael Siani hit a sacrifice fly to center in the third, scoring Brandon Crawford. Crawford doubled to start the inning and has a 15-game hitting streak against the Astros dating back to May 12, 2015.

Brendan Donovan had an RBI single, and Alec Burleson followed it up with an RBI double in the fifth to increase the Cardinals’ lead to 3-0.

After Diaz and Cabbage hit back-to-back solo home runs in the fifth, Nolan Arenado responded with a solo home run to left in the sixth.

“To be able to jump on them early and score some runs was big,” Crawford said. “Losing the first couple games, we definitely wanted to come away with the win today.”

The Cardinals finished the road trip through Cincinnati, Philadelphia and Houston with a 4-5 record, but after blowing a lead in the eighth inning on Monday against the Astros, St. Louis was able to rebound and win Wednesday’s finale.

“We needed it,” Marmol said. “After what happened in that first game, to be able to take one before we got out of here was important.”