A full house of 53,463 jammed into Dodger Stadium last night to see their darling rookie sensation Fernando Valenzuela, pitch against the Montreal Expos. But it was Montreal hurler Ray Burris who put on the show, shutting the Dodgers out on only five hits, all singles, as the Expos downed Los Angeles 3-0, evening the league championship series at one game apiece.

Burris, who fanned three, never faced more than four batters in one inning. The Dodgers' only substantial threat came in the ninth, when they put two men on with one out. But shorstop Chris Speier backhanded a line drive just off the turf and flipped to second baseman Rodney Scott for a game-ending double play.

The Expos scored twice in the second inning on singles by Larry Parrish and Jerry White, a run-scoring double into the right field corner by Warren Cromartie, and a two-out rbi single by Tim Raines.

The Expos added an insurance run in the sixth, Valenzuela's last inning, when a throw from left-fielder Dusty Baker went astray, allowing Andre Dawson to score from third.

In New York, the Yankees exploded for seven runs in the fourth inning on the way to a 13-3 shellacking of the hapless Oakland A's. The Yanks' third consecutive victory in post-season play moves them to within one game of the American League championship.

Quad Them

Craig Nettles, the star of Tuesday night's game, led the Yankee attack with four hits in four at bats, including a three run homer in the seventh. Lou Piniella, who replaced the injured Reggie Jackson in the second inning, also pounded a three-run homer, capping the seven run fourth.

Reliever George Frazier, who replaced starter Rudy May in the fourth, picked up the win, while Steve McCatty absorbed the loss.