Dave Righetti and Rich "Goose" Gossage combined to shut out the Brewers on seven hits, and Lou Piniella and Reggie Jackson hit home runs as the Yankees beat Milwaukee, 3-0, yesterday afternoon to move to within a game of winning the American League East "mini-playoff" series.

Righetti was close to untouchable for six innings, giving up just four hits while fanning ten. Only in the fourth, after Piniella had put the Yanks on top with his solo shot into the left field bleachers in the top half of the inning, did Righetti run into trouble, yielding a lead-off single to Sal Bando. Bando moved to second as Ted Simmons grounded out, but Righetti struck out Gorman Thomas and Ben Ogilvie to retire the side.

The Brewers did not threaten again until the seventh inning. Ron Davis, the winner of Wednesday night's game, came on in relief of the visibly tired Righetti and induced Bando to pop out to start the inning.

But two walks sandwiched around a Jim Gantner single loaded the bases and again, as in Wednesday's game, Gossage was called in to shut the Brewers down. A pop-up and a strikeout ended the threat, and a two-run smash by Reggie Jackson in the top of the ninth put the game on ice.

Meanwhile, in Montreal last night, the Expos went two up in their National League East championship, defeating Philadelphia, 3-1. Gary Carter's two-run homer off Dick Ruthven in the third inning proved to be decisive. Jeff Reardon pitched out of a bases-loaded jam in the eighth to save the game for starter Bill Gullickson.