Everett clinched the Northwest League North Division first-half title before it took the field Sunday night, as second-place Vancouver was beaten at home by Eugene and fell 2 1/2 games back with one to play.
That was a good thing for the AquaSox, who dropped a 7-0 decision at Boise.
"We'll take what we can get," Everett manager Rob Mummau said. "We're just happy to be in the playoffs right now."
Despite Sunday's loss, the Mariners' short-season affiliate is 23-14, having won 13 of 19 home games. The AquaSox are is undefeated when leading after six innings and 19-3 in games decided by three runs or fewer.
"It's been a combination of things -- good defense, timely hitting. We seem to be good in the clutch offensively," Mummau said. "We're really good in one-run games; over half of our wins have been in in one-run games. We're playing good baseball in tight games."
Everett's D.J. Peterson, the Mariners' top pick in this year's Draft, leads the league with six homers and 28 RBIs while ranking fifth with a .314 batting average.
"He's a good-looking kid. He's got a lot of bat speed and good plate discipline," said Mummau, who was Mariners scout from 2001-08. "He's an advanced hitter for this level and defensively, he's good at third base as well."
Peterson left Sunday's game after taking a grounder off his wrist in the first inning, but Mummau said it's not a concern for the second half.
"He'll be fine. He just took a hard one-hopper off the wrist," the skipper said. "He shouldn't be out too long at all."
So what are Mummau's concerns over the final six weeks of the season?
"A little better plate discipline. I'd like to see us a little better offensively," he said. "Our pitching could be improved in terms of locating pitches. And our baserunning could be better; we could be more aggressive on the bases."