KANSAS CITY, Mo. (AP) — Trailing by two runs and down to their last strike, the Seattle Mariners found a way to keep their winning streak alive.

“Confidence is building,” manager Scott Servais said.

Seattle became the first major league team to homer in each of its first 15 games when Dee Gordon connected in the sixth inning, then beat the Kansas City Royals 7-6 Thursday behind Daniel Vogelbach’s home run in the 10th.

Seattle improved the best record in the major leagues to 13-2, completing a four-game sweep and extending its winning streak to six. The Mariners became just the third team since 1987 to open with at least 13 wins in the first 15 games after Milwaukee (14-1 in 1987) and Boston (13-2 last year).

Kansas City has lost 10 straight games, has the poorest record in the big leagues at 2-10 and is off to its worst 12-game start since 2006. The Royals failed to preserve leads of 4-0 in the sixth and 6-4 with two outs in the ninth.

“Other teams just can’t seem to do any wrong,” said Kansas City’s Whit Merrifield, whose hitting streak ended at 31 games.

Royals center fielder Billy Hamilton was carted off with a knee injury after failing to grab Mitch Haniger’s tying, two-run triple in the ninth. Royals manager Ned Yost said he did not have an update on Hamilton’s condition.

“Hanny had the at-bat of the game,” Servais said. “You’re down to your last strike, fighting and clawing. He finally got the changeup up in the zone.”

Merrifield went 0 for 6. He had not gone hitless since Sept. 9.

“Out of my last nine outs, I feel like I’ve made six good swings on good pitches in the zone,” Merrifield said. “I either hit it on the barrel at somebody or just missed it and hit it in the air. That’s kind of what makes streaks like these so rare

The 2002 Cleveland Indians had homered in each of their first 14 games. Seattle’s 36 home runs are tied with the 2000 St. Louis Cardinals for the most in a club’s first 15 games. The Mariners have scored five or more runs in all but one game.

Vogelbach hit a 427-foot drive off Glenn Sparkman (0-1) for his sixth home run this season.

“I’m not in that situation if Hanny doesn’t have the at-bat to tie the game,” Vogelbach said. “He fouled off a ton of pitches. He made him work, and then got a pitch he could handle.”

Brandon Brennan (1-0) struck out three in the ninth, working around his own throwing error on a grounder to get his first big league win. Brennan has not allowed a run in his first 9 2/3 innings in the major leagues, holding batters to a .156 average (5 for 32).

Connor Sadzeck pitched a perfect 10th for his first professional save.

Seattle trailed 6-3 before Edwin Encarnación hit an RBI single off Wily Peralta in the eighth.

Pinch-hitter Omar Narváez and Gordon singled off Brad Boxberger with one out in the ninth and Mallex Smith took a called third strike. Haniger hit a long drive on a full count and Hamilton, who entered at the start of the half-inning for defense, allowed the ball to glance off his glove on the warning track.

Haniger, who hit a tiebreaking homer with two outs in the ninth inning on Wednesday, slid into third as two runs scored. Hamilton’s left knee hit the wall, and he crumpled to the warning track, then was unable to put weight on the knee when he got up.

SWANNY

Mariners RHP Erik Swanson made his major league debut, allowing two runs and three hits in two innings. He is the 18th player and ninth pitcher to make his Mariners debut this season.

MOVES

Royals RHP Jake Newberry was recalled from Omaha, and 1B Frank Schwindel was optioned to the Triple-A farm team.

TRAINER’S ROOM

Mariners: OF Jay Bruce was held out of the lineup with a sore left Achilles. He came out of Wednesday’s game after the third inning because of the injury. … RHP Shawn Armstrong pitched an inning Wednesday night on an injury rehabilitation assignment for Triple-A Tacoma. He is on the 10-day IL with a right-oblique strain.

UP NEXT

Mariners: LHP Wade LeBlanc (2-0, 4.76 ERA) starts a homestand opener Friday against Houston.

Royals: RHP Brad Keller (1-1, 2.84 ERA) is to be on the mound Friday against visiting Cleveland.