SEATTLE -- For James Paxton on Monday night, it wasn't how he started, but how he finished. The big left-hander picked up his first win of of the season while the Mariners edged the Astros, 2-1, at Safeco Field, sending the defending World Series champs to their fifth loss in

SEATTLE -- For James Paxton on Monday night, it wasn't how he started, but how he finished. The big left-hander picked up his first win of of the season while the Mariners edged the Astros, 2-1, at Safeco Field, sending the defending World Series champs to their fifth loss in six games.

The Mariners continued their strong start, improving to 9-5 with their fifth win in their last six games. The Astros have lost three straight, falling to 10-7 and dropping into third in the early American League West race behind the Angels (13-3) and Mariners.

Paxton surrendered a homer to George Springer leading off the game, then buckled down and held the Astros scoreless for the rest of his six-inning outing. He allowed just three hits with three walks and seven strikeouts, lowering his ERA to 4.57 through four starts.

"It's all about just getting back to what I'm trying to do there and making one pitch at a time," Paxton said. "I can't let one hit, one home run take me out of my game. I was just focused on making my next pitch."

He wound up making plenty of good ones, holding the Astros to just a pair of singles the rest of his outing as Houston managed just three hits for a second straight game.

This was the Paxton the Mariners need to compete this season, as he's proven capable of dominating over the past two years when he stays healthy and on point. Paxton had the highest average fastball velocity of any left-handed starter in the Majors over his first three starts at 95 mph, and he didn't waste time building on that on a cool night at Safeco.

"He came out firing tonight," said Mariners manager Scott Servais. "He didn't need a couple innings to build up the velocity. You saw it right out of the gate. He knows he needs to get after it early with the club and all the right-handed hitters they've got."

The Mariners tied the game, 1-1, on Nelson Cruz 's third homer of the year -- and first since coming off the disabled list on Saturday -- in the fourth and then took the lead on back-to-back doubles by David Freitas and Dee Gordon in the sixth.

• Cruz launches first homer since coming off DL

Dallas Keuchel allowed two runs on six hits while pitching all eight innings for the Astros, but the lefty fell to 0-3 with a 3.52 ERA.

Nick Vincent, Juan Nicasio and Edwin Diaz held the Astros hitless over the final three frames, with Diaz notching his AL-leading seventh save for Seattle.

"We're playing well, trying to get all our pieces back," said Gordon, who has hit safely 12 of his first 13 games with the Mariners for a .322 average. "We just have to keep it going. Paxton has been pitching amazing his last three starts. [ Felix Hernandez ] pitched awesome yesterday. Sugar [Diaz] is doing his thing. The offense, we're trying to click with guys out and we just have to keep doing it."

MOMENTS THAT MATTERED

Haniger to the rescue:Mitch Haniger has carried a big bat this season, with a Mariners-leading 15 RBIs, but the right fielder delivered with his glove in the sixth inning to help preserve Paxton's one-run outing. WIth Carlos Correa on first and one out, Haniger raced into the gap in right-center to haul in a line drive by Yuli Gurriel on a play rated a 5-star catch by Statcast™, it's highest ranking, with just a 25 percent catch probability. Haniger covered 75 feet in 4.5 seconds for just the second 5-star catch of his career, the other coming in 2016 with the D-backs.

"He made a great read and that's about as far as he could reach to grab it," said Servais. "I'm glad he's got a glove as big as it is. We needed every inch of it. He's a really good player. We talk a lot about his at-bats and driving the ball out of the park. But he's a good baserunner, the defense is there and he comes to play every night."

Doubles do it: The Mariners pushed across the winning run on the doubles by Freitas and Gordon. Freitas drove a shot down the left-field line and hustled into second on a pretty nice play for a catcher, then scored when Gordon looped a shot into right-center and Springer slipped while trying to get over from a pretty extreme outfield shift. Gordon is known for his speed, but he gave a hat tip to Freitas for putting himself in scoring position.

"That was a big play, probably the biggest play of the game, him getting to second right there," said Gordon.

SOUND SMART WITH YOUR FRIENDS

After a leadoff walk and stolen base by Carlos Correa in the ninth, Diaz struck out the final two batters he faced -- Josh Reddick and Marwin Gonzalez -- to become just the second Mariner closer with seven saves in the first 14 games of a season. The other was Kazuhiro Sasaki in 2001.

WHAT'S NEXT?

Ariel Miranda will be recalled from Triple-A Tacoma to start Tuesday night's 7:10 PT contest against Lance McCullers and the Astros in the first game Seattle has needed its fifth starter. Miranda gave up five hits and three runs in four innings at Fresno on Wednesday in his second Minor League outing of the season. The 29-year-old lefty was 0-2 with a 4.70 ERA in seven games (six starts) against Houston last year.