Updated

Seattle's top pitching prospect Taijuan Walker makes his much anticipated big league debut on Friday when the Mariners continue a four- game set with the Houston Astros at Minute Maid Park.

Walker, the Mariners' first pick in the 2010 draft, started his season with Double-A Jackson and went 4-7 with a 2.46 ERA before being promoted to Triple- A Tacoma, where he was 5-3 with a 3.61 ERA in 11 games.

Over his last two starts, though, he has pitched to a 0.82 ERA. He's also struck out 160 batters in 114 1/3 innings.

"I just want him to go out there and do what he does, just be himself, enjoy the experience and have fun," Mariners manager Eric Wedge said. "Hopefully, he'll be able to allow himself to relax and have fun with it. That's the best way to have early success, just really enjoy the moment."

Walker, who turned 21 on Aug. 13, will become the fifth-youngest player in Mariners history to start a game.

In Thursday's opener, Franklin Gutierrez had a two-run home run and Nick Franklin also went deep, as Seattle snapped a six-game losing streak with a 3-2 win.

Erasmo Ramirez (5-1) gave up two runs on five hits while fanning seven and walking two over 5 2/3 innings for the Mariners.

"Erasmo did a great job tonight. He pounded the strike zone and threw strikes when he needed to. Overall we did really well," said Franklin.

Brett Wallace had a home run while Jason Castro drove in the other run for the Astros, who have lost three straight.

Jordan Lyles (6-7) gave up all three runs on four hits and a pair of walks over six frames in the opener of this four-game series.

"I wasn't getting that down action on my pitches. I had a lot of fly outs and the outfielders did a heck of a job out there running down balls," said Lyles.

Heading to the hill for Houston on Friday will be righty Brad Peacock, who has won his last two starts. Peacock beat the Toronto Blue Jays on Saturday, holding them to four runs and six hits in 5 2/3 innings to run his record to 3-4 to go along with a 5.67 ERA.

Peacock has faced the Mariners twice this season and is 1-1, despite a 9.64 ERA.

Seattle has won eight of 13 from the Astros this season and has won six of the last seven matchups.