Willson Contreras belted a three-run homer and Pedro Pages added a solo shot to lead the St. Louis Cardinals to a 9-1 win and a sweep of a day-night doubleheader on Wednesday against the host Cincinnati Reds.

After hitting four home runs to win Game 1 by a 6-0 count, the Cardinals broke to a 9-0 lead in the first three innings of the nightcap.

St. Louis gave a rude welcome to highly touted Reds right-hander Chase Petty in his major-league debut.

Lars Nootbaar worked a leadoff walk before Masyn Winn singled to right. After Elly De La Cruz made a diving grab of a Brendan Donovan line drive for the first out, Willson Contreras crushed a middle-of-the-plate fastball 421 feet off the batter’s eye in center for a three-run homer and a 3-0 St. Louis lead.

Pedro Pages made it 4-0 St. Louis in the second inning when he drilled a Petty fastball into the seats in left for his second homer of the season.

Petty could only retire one batter in the third as the Cardinals chased the rookie with five more runs. Petty (0-1) was charged with nine runs on seven hits over 2 1/3 innings, walking two and striking out three.

With the Cardinals reverting to six starters, Steven Matz returned to the rotation for his second start of the season and ninth appearance.

Matz couldn’t make his 9-0 lead pay off with a win as Cincinnati drove his pitch count up to 73 pitches through four innings with five hits. Matz struck out six and walked none, but was relieved by right-hander Gordon Graceffo to start the fifth. Graceffo (1-0) allowed a run on two hits over the final five innings to earn his first Major League win.

De La Cruz extended his hitting streak to 14 games and his on-base streak to 19 with a swinging bunt in the third inning. The hit measured two feet beyond home plate and rolled to the third-base line, where Pages touched it before it rolled foul. De La Cruz followed with a more conventional single to center to open the sixth and went on to score the Reds’ lone run.