KANSAS CITY -- It took a little longer this time, but the Mariners continued making history -- and hitting home runs -- with Mitch Haniger delivering the dramatic blow in a 6-5 win over the Royals on Wednesday night at Kauffman Stadium.

Haniger waited until two out in the ninth inning to launch his opposite-field homer off reliever Brad Boxberger, lifting Seattle to its fifth straight win and a franchise-best 12-2 start to the season. It also extended the club’s streak of 14 straight games with a home run to open the season, tying the 2002 Indians for the MLB record.

Last year’s World Series champion Red Sox and the 2012 Rangers are the only other American League teams to open a season at 12-2 since 1990.

The Mariners have hit 34 homers on the season -- tied with the 2000 Cardinals for the most by any team in its first 14 games -- and none have been bigger than Haniger’s, which broke a 5-5 tie and handed the Royals their ninth straight loss.

Seattle has scored six or more runs in 12 of its first 14 games, the first team in the Majors to do that since 1908.

“Honestly, in Spring Training when we got this squad together, I knew we were going to have a really good lineup,” said Haniger, one of the few holdovers on a team with 15 newcomers on the 25-man roster. “We’re off to a really good start and that’s great. We just have to keep trying to get better, keep learning, and focusing on one day a time.

“We have a lot of really good veterans in here who help the younger guys and a lot of really good players. We just have to stay greedy at the plate and don’t be satisfied with what’s happened in the last couple weeks.”

Haniger’s go-ahead blast came on an 0-1 fastball from Boxberger after he’d been late on a first-pitch slider.

“I saw it well, I just waited way too long,” Haniger said. “Based off that, I thought he might try to sneak a heater in since if you’re late on an offspeed pitch, a lot of times you’re going to come back with a fastball.”

Reliever Roenis Elias had to wiggle out of a bases-loaded jam in the bottom of the ninth for his second save of the season.

Kikuchi still seeking first win

Mariners lefty Yusei Kikuchi missed a chance at his first Major League win as the 27-year-old from Japan allowed three runs on five hits over six innings in an 80-pitch outing, but the bullpen couldn’t hold his 5-3 lead.

Kikuchi gave up a pair of long solo home runs -- a 453-foot blast by Hunter Dozier and a 454-footer by Jorge Soler -- before settling in and retiring the last 10 batters he faced. Kikuchi has left all four of his starts with the Mariners holding a lead.

“He cramped up in his [left] calf when he came off and that was going to be it anyway,” manager Scott Servais said. “Getting six innings out of him was great. He gave us a good chance to win. We’ve got to get him a ‘W.’ He’s left the game with some leads, we just haven’t held them.”