After spending the better part of a week on the edge of elimination against Oakland in the division round, the Yankees have taken a huge stride toward their fourth straight championship.
They own a five-game winning streak and will resume their quest for the American League title on Saturday at home, having three games at Yankee Stadium in which to achieve the two additional victories needed to dispose of the Mariners.
Mike Mussina retired the last eight batters he faced to make it through six innings and pick up the victory, but he had to make a series of big pitches early in the contest to prevent the powerful Seattle offense from getting untracked.
Seattle's Freddy Garcia had a difficult second inning, but did not allow more than one base runner in an inning during the remainder of his 7 1/3-inning stint.
Tino Martinez led off the New York second with a single and advanced on a walk to Jorge Posada. Paul O'Neill flew to left for the first out of the inning, but Brosius then doubled to left, scoring both runners.
Knoblauch delivered a two-out single to center that drove in Brosius with what proved to be the deciding run. Seattle center fielder Mike Cameron appeared to have had a chance to catch Knoblauch's sinking liner if he had left his feet, but he wound up trapping the ball.
Seattle failed to take advantage of a series of chances against Mussina.
The Mariners put runners on first and second with one out in the opening inning, but Edgar Martniez ended the threat by grounding into a double play.
Seattle had runners on first and third with two out in the second only to have David Bell strike out on a 3-2 pitch. Ichiro Suzuki reached to lead off the third on a two-base error by center fielder Brnie Williams, but the Seattle superstar could advance only as far as third.
The Mariners broke through in the fourth when Cameron was hit by a pitch with one out and promptly scored in front of Stan Javier's homer to center.
Ramiro Mendoza replaced Mussina in the seventh and gave up a one-out single and then walked Suzuki intentionally with first base open and two away. Mendoza ended the inning by getting Mark McLemore to ground to first.
New York closer Mariano Rivera came on with one one and one out in the eighth and retired all five men he faced. It was the 23rd playoff save of Rivera's career.