Justin Smoak and Michael Saunders each hit a two-run home run to pace Seattle's 9-6 victory over Kansas City in the second-test of a four-game series.
Miguel Montero added three hits and two RBI, while Kyle Seager also drove in a pair for the Mariners, who have won the first two of the set.
Recalled from Triple-A Tacoma, Blake Beavan (4-6) did enough to snag the win, allowing seven hits and five runs over six-plus innings.
Lorenzo Cain hit a two-run shot and Alex Gordon totaled two hits with an RBI for the Royals, who have dropped seven of eight.
Ryan Verdugo's (0-1) big league debut lasted 1 2/3 innings, during which he surrendered eight hits and six runs.
"We found ourselves in a hole early and we found a way to get their bats going," said Royals manager Ned Yost. "Ryan came in and got two outs and it caved in on him from that point."
The Royals managed to make a late charge, closing within 9-6 in the home seventh.
Beavan allowed a single to Jeff Francoeur and a double to Salvador Perez before yielding to Charlie Furbush, who departed with an arm injury after giving up a run-scoring groundout to Chris Getz.
Shawn Kelley came on, but promptly served up Cain's pinch-hit blast, then Lucas Luetge allowed a Gordon single before inducing an inning-ending double- play grounder from Alcides Escobar.
KC went quietly in the eighth against Luetge then Tom Wilhelmsen followed suit in the ninth for his eighth save.
Seattle smacked around Verdugo early, scoring three times in the first on Montero's RBI double and a two-run homer from Smoak.
The Mariners came up with three more to chase Verdugo in the next frame thanks to a single from Montero and two-run double by Seager. Vin Mazzaro was called upon and fanned Miguel Olivo to limit the damage at 6-0.
"You get hits. You keep having good at-bats. The pitcher's going to throw more pitches. That makes him work and he's bound to make a mistake," Smoak said about getting to the opposing starter early on. "If he's out there in his groove and he's doing what he wants to do you're not going to get too many hits."
The hosts responded with three in the third on a Gordon triple and RBI hits from Escobar and Billy Butler, but a two-run shot by Saunders and a run- scoring triple from Dustin Ackley in the fifth put Seattle ahead by a 9-3 count.
The Mariners lead the majors with 238 runs scored on the road and, coming into the game, ranked third overall away from home, averaging 4.87 runs per game...Seattle optioned pitcher Steve Delabar to Tacoma to make room for Beavan...Mazzaro was also recalled from Omaha, while pitcher Jonathan Sanchez was designated for assignment and outfielder Jason Bourgeois was optioned to Omaha.