Robin Yount's 14th homer of the season, leading off the Milwaukee 10th inning last night, gave the Brewers a 3-2 victory over the visiting Seattle Mariners and put them in first place in the AL East, a half-game ahead of idle Baltimore.

Chuck Porter (6-5) gave up eight hits for his sixth victory in his last seven decisions as the Brewers won their seventh game in eight starts. Yount, whose last home run was July 16, hit the first pitch from Bob Stoddard (6-13) into the left-center field bleachers.

Roy Thomas, who relieved Seattle starter Matt Young to start the eighth, gave up the tying run as his string of 20 straight shutout innings ended.

Ed Romero singled with one out in the eighth and Yount walked. Ted Simmons lined an 0-2 pitch to right for a single, scoring Romero and tying the game, 2-2.

Before the game, the Brewers announced that Pete Vuckovich, who hasn't pitched this season because of a rotator cuff injury, has been reactivated. Vuckovich was the AL's 1982 Cy Young Award winner. The Brewers put Bob McClure on the 21-day disabled list with a strained back muscle.