The Milwaukee Brewers’ Ben Gamel stands in the on-deck circle during the second inning against the Cardinals on Monda in St. Louis. (AP photo)

ST. LOUIS — Dakota Hudson and two relievers combined on a one-hitter, and Paul DeJong homered to lead the St. Louis Cardinals over the Milwaukee Brewers 3-0 Monday night in the series opener between NL Central contenders.

Yasmani Grandal’s ground-rule double with two outs in the eighth inning off Giovanny Gallegos was Milwaukee’s only hit. Hudson was lifted with two outs in the seventh after throwing 111 pitches, and Andrew Miller got four outs for his fifth save.

St. Louis pulled out to a half-game lead over division rival Chicago Cubs, who were idle. Third-place Milwaukee is three games back.

Hudson (12-6) matched a career high with seven strikeouts and walked four — including his final batter, Eric Thames. Gallegos entered and retired Ben Gamel on a grounder to end the inning.

Orlando Arcia reached on an error by DeJong at shortstop to begin the eighth before Gallegos got two outs. Grandal then hooked a 1-2 slider just inside the right field line and the ball bounced into the stands.

Miller relieved and, after an intentional walk to Christian Yelich, got Mike Moustakas to ground out with the bases loaded. Miller then closed it out in the ninth.

Milwaukee’s best chance for a hit against Hudson came in the sixth when Trent Grisham hit a hard grounder up the middle. DeJong made a diving stop and threw out Grisham at first base.