A handwritten sign hastily taped above the little corner of the Royals clubhouse where Sean O'Sullivan and three of relievers have their locker stalls told the story:

"Shut Out Wall."

That's what it said, and that's what they did. O'Sullivan, making his first start of the year, combined with relievers Tim Collins, Jeremy Jeffress and Aaron Crow to blank the slumping Mariners 7-0 Saturday, continuing a surprising getaway that's vaulted the Royals into first place in the AL Central.

"You've got to give credit to the rest of the guys in this locker room and the way they're playing the game," said O'Sullivan (1-1). It's fun to show up at the park right now."

Alex Gordon had three hits, raising his league-leading total to 22, and drove in two runs and Mike Aviles had three RBIs as the Royals beat 2010 Cy Young winner Felix Hernandez and handed the Mariners their 11th loss in 13 games.

"The bullpen did a great job," Royals manager Ned Yost said. "They shut the door on everything. Collins has three pitches he can use to get big league hitters out. Jeffress can overpower you. And Crow's been dynamite. It was a great job pitching-wise all the way around."

O'Sullivan threw five shutout innings, allowing five hits and two walks, striking out four. He was helped by shortstop Alcides Escobar's run-saving defensive play on a hard-hit grounder by Ichiro Suzuki, who was 0 for 5 and had his Kauffman Stadium hitting streak stopped at 16 games.

Only two of the five runs charged against Hernandez (1-2) were earned. He took his second straight loss after going five innings and giving up six hits. He walked two and struck out six.

Seattle manager Eric Wedge kept the clubhouse closed for several minutes while he talked to his slumping team.

"I had a few choice words for them," he said. "I'm not real happy right now. I made it very clear as to how we're going to go about our business."

The Mariners stranded 11 runners and were 0 for 9 with runners in scoring position.

"We just didn't play good baseball at all today. That's what (angers) me off more than anything," Wedge said.

Gordon extended his hitting streak to 10 games, longest active in this majors this year, with a leadoff single in the fourth and eventually scored on Melky Cabrera's sacrifice fly.

In the fifth, third baseman Chone Figgins was charged with an error when Escobar's sharply hit grounder skipped over his glove. With two outs, Chris Getz singled and Gordon delivered a two-run double over the head of center fielder Ryan Langerhans. Billy Butler followed with an RBI single for a 5-0 lead. Gordon added a single in the eighth and came around on Aviles' two-run double off Brandon League.

Collins threw a shutout inning, Jeffress threw two scoreless innings and Aaron Crow worked a 1-2-3 ninth.

"The bullpen's been phenomenal," said O'Sullivan. "It's been a come-in-and-lock-the-door deal. They've been great."

In the Seattle third, with Brendan Ryan on second with a double, Suzuki hit a hard grounder up the middle. It looked like an RBI single but Escobar dived to his left, stopped the ball and jumped to his feet to throw out one of the fastest runners in the league. Ryan stopped at third and was stranded when Figgins hit a routine grounder to Escobar.

"Man, that was huge. Huge!" said O'Sullivan. "He hit it, it went past my feet and I'm going, 'OK, that's through the middle for sure.' It had a little heat on it. It wasn't a chopper. For him to get to that ball and get to his feet quick enough to make the throw was great."

Cabrera doubled in the second and scored on Aviles' RBI single.

The Mariners loaded the bases with one out in the fourth on two singles and a walk. But O'Sullivan retired Michael Saunders on a shallow flyball to left and struck out Chris Gimenez.

NOTES: Collins gave up a walk and a double but struck out the side in the sixth. ... Figgins practically knocked Jeffress down with a line drive in the seventh that rocketed into the surprised reliever's glove. The rookie reliever struck out Saunders in the eighth with a 100 mph fastball. ... Seattle's Josh Lueke retired the side in the seventh on four pitches. ... Seattle C Miguel Olivo, on an 0-for-25 slump, was out of the lineup.