Split-season playoffs got underway with a blast yesterday when the Houston Astros and the Oakland A's used round-trippers to gain 1-0 leads in their divisional series with Los Angeles and Kansas City respectively.

Astro Alan Ashby smashed a shot homer to right with one on and two out in the bottom of the ninth inning to give Houston a 3-1 victory over Los Angeles, in the Astrodome.

Most of the game was a pitching duel between Astro fastballer Nolan Ryan and Dodger rookie sensation Fernando Valenzuela. Neither team's hitters could mount serious threats until the bottom of the sixth.

Ryan ended the Dodger sixth when he tallied his fifth strikeout of the game to dismiss Valenzuela and run his string to fourteen straight outs. Valenzuela took the mound and retired the first two Astros.

But Terry Puhl looped a single to right and took second on a walk. Left fielder Tony Scott lifted a Texas leaguer to right center. Davey Lopes dashed back for it while Kenny Landreaux hurried in from center field. Neither one could reach the ball in time, and Puhl scored easily from second.

Houston didn't hold the lead for long, though, as the Dodgers responded in the top of the seventh. Iron man Steve Garvey plastered a one-out pitch, tying the score with his solo shot.

Ryan and Valenzuela continued their battle, until Valenzuela was relieved by Dave Stewart in the bottom of the ninth. Stewart blew fast balls by Cesar Cedeno, made Art Howe fly to center, then gave up a pinch-hit single to Craig Reynolds. Ashby followed with his three-run homer.

Wayne Gross slammed a three-run homer and Mike Norris hurled a four-hitter as the Oakland A's blanked the Kansas City Royals 4-0, in the first game of the American League West division playoffs yesterday in Kansas City.

Gross--a .206 hitter on the year--blasted a 2-1 Dennis Leonard fastball over the right-field fence in the fourth after George Brett's throwing error kept the inning alive.

Dwayne Murphy's solo shot in the eighth inning rounded out the scoring.

Norris, who finished this year 12-9, baffled the Royals with his repertoire of change-ups. All four Royal hits were singles, but Norris didn't have a carefree outing. In both the third and fifth innings the Kansas City veteran worked his way out of bases-loaded jams.

Despite the homers, Leonard turned in a fine performance in defeat. He allowed just seven hits and one earned run in eight innings of work.