SEATTLE -- When a team wins 11-3, the manager usually doesn't point to his starting pitcher getting out of jam in the first inning as the key to the game.

However, Baltimore's Buck Showalter is not the typical manager.

After the Orioles' Tim Beckham led off the game by hitting the first pitch from Seattle's Yovani Gallardo out of the park, Baltimore starter Kevin Gausman ran into problems of his own in the bottom of the inning.

Jean Segura and Yonder Alonso hit back-to-back doubles to tie the score, and Robinson Cano reached on a single that fell just in front of right fielder Seth Smith.

Alonso had to wait about 10 feet off the base to see if the ball was going to be caught and nearly was thrown out scrambling to get back to second, with shortstop Beckham's throw sailing into right field for an error.

That put runners at second and third with no outs, and Nelson Cruz, the American League's RBI leader, coming to the plate.

Gausman responded by striking out Cruz and Kyle Seager, the Nos. 4-5 batters in the Seattle lineup, then got Guillermo Heredia to ground out to short to end the inning.

The Orioles scored six runs in the second, highlighted by a Manny Machado grand slam, and cruised from there.

"I told (Gausman) when I took him out of the game, 'That's the ballgame, you won the game in the bottom of the first,'" Showalter said. "You know, a lot happened between then and the end, but that was huge. He got back off the mound to collect himself and try to minimize the damage and get us back in the dugout."

Showalter also pointed to a play in the bottom of the fifth, after the Orioles took a 10-1 lead.

Mike Zunino hit a solo homer leading off the inning, and speedy Jarrod Dyson walked. Segura flied out to the warning track in center field, and Dyson tried to tag and take second. Adam Jones threw out Dyson, thwarting any comeback hopes.

"Adam made a big play throwing a guy out at second, believe it or not, because there was some momentum working in that inning," Showalter said. "They've got such a lethal lineup, you know just how quickly leads can evaporate ... especially on the road."

Gausman (9-8) pitched seven innings, allowing two runs on six hits. He walked one and struck out six.

"I knew if I made good, quality pitches I had a chance to get out of the (first) inning," Gausman said. "When I get a lead like that, I need to shut the door. In New York, I got a 9-1 lead and then it's 9-9. You have to win that game and grind through it."

Seth Smith and Trey Mancini also homered for Baltimore (59-60), which moved past the Mariners (59-61) -- who dropped to 0-5 on their seven-game homestand -- in the American League playoff race. The Orioles closed within two games of the idle Los Angeles Angels for the second and final AL wild-card berth.

"We've had our ups and downs, injuries, guys not producing like they should be," said Machado, whose homer was his 23rd of the season and his second slam (sixth career). "We just need to keep doing what we're doing. (Gausman) gave us an opportunity to go out there and do some damage. He's pitching well."

Gallardo (5-8), acquired from Baltimore in an offseason trade for Smith, allowed eight runs on nine hits in four-plus innings. He walked one and struck out four.

Beckham opened the game with a shot over the right field wall. It was his 16th homer of the season and his first career leadoff homer.

The Orioles pulled away with a six-run second off Gallardo, sending 11 batters to the plate.

With one out, Mark Trumbo doubled to center field. Chris Davis hit an RBI double off the wall in left, just over the outstretched glove of Heredia. A single by Smith moved Davis to third, and Davis scored on Caleb Joseph's chopper up the third base line.

A single to right by Beckham loaded the bases for Machado, who hammered a 1-2 pitch from Gallardo over the Mariners' bullpen and the out-of-town scoreboard in left field. The ball was caught by a fan sitting in the front row of the second deck, 430 feet from the plate.

The Orioles extended the lead to 10-1 in the fifth.

Jones led off the inning with a double, ending Gallardo's night.

Reliever Casey Lawrence struck out the first two batters he faced before Davis hit a run-scoring single up the middle and Smith launched a two-run homer to right field, his 12th of the season.

Zunino hit his 18th homer of the season, a solo shot leading off the bottom of the fifth, to make it 10-2.

Mancini led off the seventh by hitting Lawrence's first pitch over the right field wall. It was Mancini's 21st homer.

Cruz closed the scoring with a solo shot leading off the bottom of the ninth. It was his 29th of the season and increased his RBI total to 95.

"Obviously, we have not played well at home over the past five games, for a number of reasons," Mariners manager Scott Servais said. "We had a chance to get on their starter early in the first inning, that's when they're most vulnerable, and we got one. Then they put up a big number on Gallardo."

NOTES: Seattle SS Jean Segura fouled a ball off his left shin in the fifth inning and had to be attended to by manager Scott Servais and trainer Rick Griffin. Segura stayed in the game. ... CF Adam Jones had two hits to give him 1,575 with the Orioles, passing Boog Powell for fifth in franchise history. ... The Mariners recalled RHP Thyago Vieira from Triple-A Tacoma and optioned RHP Christian Bergman to the Rainiers. Vieira, 24, became the fourth Brazilian-born player to ever appear in the major leagues, and the second pitcher, when he made his debut with a scoreless ninth inning. ... Orioles LHP Wade Miley (6-9, 5.19 ERA) faces Mariners LHP Andrew Albers (2017 debut) on Tuesday.