DETROIT (AP) - Alex Gordon had already struck out three times when he came to the plate with the bases loaded in the 10th inning.
"I was just trying to make contact," the Kansas City outfielder said.
He ended up hitting his first career grand slam, helping the Royals to an encouraging win at the end of a difficult road trip.
Gordon's drive highlighted a five-run 10th for Kansas City, which rallied against the Detroit bullpen for an 8-3 victory Thursday after Tigers ace Justin Verlander left with a blister on his thumb.
George Kottaras put the Royals ahead 4-3 with a bases-loaded walk off Phil Coke (0-3). Darin Downs came on for Detroit after that, but Gordon broke the game open one out later with a homer that easily cleared the 420-foot marker on the wall in center.
"That's a big outfield," Gordon said. "I think there was a storm coming in that kind of blew it out a little bit."
The game started after a 30-minute rain delay, another interruption in an unusual trip for the Royals. Kansas City had a game at Boston last Friday postponed because of the manhunt for a suspect in the Boston Marathon bombings.
When the Royals arrived in Detroit for what was supposed to be a three-game series, the opener was rained out Tuesday.
Kansas City has not played a home game since April 14. Since then, the Royals have played seven road games in 11 days. They adjusted fine to the unexpected days off and finished the trip with a two-game split against the Tigers, leaving Comerica Park in first place in the AL Central.
The Royals went 4-3 at Atlanta, Boston and Detroit.
"This was a phenomenal road trip for us," said right-hander James Shields, who pitched eight solid innings Thursday. "We're going to look back at this road trip, and I think it's going to be a pretty crucial road trip."
The Royals will be back home Friday night against Cleveland.
Verlander is day to day with what the Tigers said was cracked skin on his throwing thumb. He and manager Jim Leyland described the injury as a blister.
"It developed a little in my last start. Started getting a little bit worse after the fifth, and I started to notice it," Verlander said. "I didn't want to risk it becoming something that I might have to deal with in my next start and the start after that, and then it turns into a month. This way, it isn't an issue. That's why I got out of there."
The right-hander allowed two runs -- one earned -- in seven innings and left with a 3-2 lead. Bruce Rondon gave up the tying run in the eighth in his major league debut.
Tim Collins (1-0) pitched a scoreless ninth for the Royals and got the win.
Rondon, the hard-throwing 22-year-old who was a candidate in spring training to become Detroit's closer, began the season in the minor leagues but was called up this week.
Jose Valverde is back with the Tigers, trying to show he can handle the closer spot again, and Rondon came on for the first time Thursday.
He reached 100 mph according to the Comerica Park scoreboard, but Billy Butler led off against him with a single, and pinch-runner Jarrod Dyson stole second. Dyson eventually scored on Lorenzo Cain's sacrifice fly.
Coke looked sharp in the ninth but lost his control in the 10th as rain began falling harder at Comerica. Cain doubled with one out, and Coke walked Mike Moustakas. After a wild pitch moved the runners to second and third, Jeff Francoeur was walked intentionally, and Coke still couldn't find the plate against Kottaras.
Downs got Chris Getz to ground into a forceout at the plate, but Gordon's second homer of the year added four more runs.
Miguel Cabrera opened the scoring with an RBI single in the first, but Butler drove in a run with a single in the third. Butler had three hits on the day and improved to 23 for 55 (.418) off Verlander, the best mark of anyone with at least 30 at-bats against the Detroit ace.
Salvador Perez of Kansas City and Jhonny Peralta of Detroit each hit sacrifice flies in the fourth.
Torii Hunter's run-scoring single in the fifth gave the Tigers a 3-2 lead.
Verlander allowed eight hits, walked one and struck out four.
Shields, acquired from Tampa Bay in an offseason trade in an effort to bolster Kansas City's starting rotation, allowed three runs and five hits in eight innings. He walked three and struck out four.
"I felt I was in a good rhythm. I was making my pitches when I needed to," Shields said. "That's a tough team over there. Even if you're making your pitches, they're still going to hit you. I think I minimized my damage as well as I could."