Yesterday, on the busiest day in baseball playoff history, the Expos, Astros, A's, and Yankees moved one step closer to a berth in the league championship series.

Tim Wallach and Chris Speier combined for the winning run in the second inning off Steve Carlton as the Montreal Expos beat the World Champion Philadelphia Phillies 3-1 in the first game of their best-of-five series for the National League East Championship.

The Expos, who obtained a playoff berth for the first time in the team's 13-year history by winning the second half of baseball's first split season, took the lead in the first when Jerry White scored on Gary Carter's double.

The Phillies tied the game in the next inning on Keith Moreland's lead-off home run, but the Montreal starting pitcher, Steve Rogers, and ace reliever, Jeff Reardon, held the Phillies at bay the rest of the way.

The Expos scored single runs in the second and fourth innings to gain their first playoff victory ever.

In the National League West Division playoffs, the Houston Astros now have a 2-0 edge over the Los Angeles Dodgers after pinch-hitter Denny Walling's two-out single with the bases loaded in the bottom of the 11th inning gave them a 1-0 victory over L.A.

The loser for the second day in a row was reliever Dave "Smoke" Stewart. who came on in the bottom of the 11th and yielded back-to-back singles by Phil Garner and Tony Scott. Cesar Cedeno was then walked to load the bases, and the stage was set for Walling's heroics.

The winner was Joe Sambito, who entered the game in the top of the 11th inning, and escaped trouble after yielding a double to pinch-hitter Steve Yeager.

Tony Armas had four hits, including two doubles, driving in both Oakland runs, and Steve McCatty outpitched rookie Mike Jones to give the A's a 2-1 victory over the Kansas City Royals and a 2-0 lead in the American League Western Division playoffs.

Armas slugged a double through the legs of third baseman George Brett in the eighth, knocking in Dwayne Murphy with the winning run. However, after the hit, Armas had to leave the game because of soreness in the left side of the groin area.

Oakland got its first run in the first inning, when Murphy scored on Armas's double. The Royals scored their only run in the fifth on 2-out singles by John Wathan, U.L. Washington, and Willie Wilson.

In the opening game of the American League East Division playoffs, the New York Yankees defeated the Milwaukee Brewers 5-3. Rick Cerone lined a two-out double to cap a four-run New York fourth inning, and the Yankees rode brilliant relief pitching by Ron Davis and Rich Gossage to the victory.