Dylan Cease allowed just two hits in 8 1/3 innings on Wednesday and Manny Machado homered twice as the San Diego Padres blanked the visiting Houston Astros 4-0 to win a tight, well-played interleague series between playoff contenders.

Cease (14-11) mowed down the first 15 hitters he faced before Jason Heyward led off the sixth with a clean single to right. Cease retired the next nine men before Mauricio Dubon started the ninth by legging out an infield single, followed one out later by an error that put runners at first and third.

Tanner Scott came out of the bullpen and got the final two outs for his third save with San Diego and his 21st overall. The Padres (87-66) maintained a 2 1/2-game lead on Arizona for the National League’s first wild-card spot and moved within three games of the Los Angeles Dodgers for first place in the NL West, pending the outcome of their game in Miami.

Houston (82-70) saw its American League West lead over the Seattle Mariners fall to 4 1/2 games. Seattle played at home later Wednesday against the New York Yankees.

Framber Valdez (14-7) nearly matched Cease pitch-for-pitch until the bottom of the sixth. Machado barreled a first-pitch sinker, lining it over the left-center field wall for the only run Cease needed.

Valdez lasted seven innings, permitting five hits and a run with two walks and six strikeouts.

San Diego broke it open against Valdez’s replacement, Kaleb Ort, in the eighth with three straight homers in a nine-pitch span. Fernando Tatis launched his 19th of the year to left-center, followed by Machado’s 29th to left and Donovan Solano’s seventh, also to left.

The Padres created a pair of scoring chances early but couldn’t convert. Valdez induced a double play grounder to get out of trouble in the second, then fanned Tatis and got a groundout from Machado to strand men at second and third an inning later.

Rookie Jackson Merrill collected three of San Diego’s nine hits.