The Blue Jay's Roy Halladay pitched his 10th career shutout Monday night against the Mariners. The outing lowers his earned run average for the season to 2.90, sixth best in the American League.

Halladay limited baseball's worst team to four hits in his sixth complete game of the season. His 10th shutout ties him with Mark Mulder for 10th place among active pitchers. Tim Hudson, at 11, is the only guy ahead of him still in his prime, so there's a good chance Halladay will spend considerable time in the second half of his career as the active leader.

A No. 1 starter is not considered one who merely gets the nod on Opening Day, it's one who has the capability of dominating every time out and does more often than he doesn't.

Halladay used the Safeco Field mound to hold a clinic on mastery of pitches. He placed his sinker, cutter and change where he wanted, when he wanted and it resulted in a masterful 2-0 win over the Mariners in front of 30,179.

"He was good," Ichiro Suzuki told the Seattle Post-Intelligencer. "That's the kind of pitcher you call an ace. It's hard to say (if that's the best I've seen him), but he was definitely good."

Halladay, the major league leader in innings pitched, struck out six and threw 115 pitches, 84 for strikes. He did not walk a batter and only two putouts were made by the Blue Jays outfield.

"It's nice when you go out and feel like everything is there and it's going to be one of those good ones," Halladay said.

The performance was a quick turnaround for Halladay, who was battered for nine hits and a season-high five earned runs against Cincinnati last week. During his side session between starts, Halladay worked on his mechanics and found a groove with his pitches.

Halladay (9-6) won for the first time since June 8, throwing his sixth complete game of the season.