ST. LOUIS (AP) — The St. Louis Cardinals are the first major league team to 50 wins, and they are focused on continuing their success.

Michael Wacha pitched six solid innings, Xavier Scruggs had three hits and the Cardinals beat the Chicago Cubs 8-1 on Saturday night for their fifth straight win.

Jason Heyward reached four times as St. Louis improved to a major league-best 28-7 at home with its eighth consecutive win at Busch Stadium. The major league-best Cardinals (50-24) have five winning streaks of five games or more this season.

"We're not completely oblivious to it, but we're not spending a lot of time on it," manager Mike Matheny said of the team's record. "It's nice watching the bulk of these guys have success."

Wacha (10-3) allowed one run and six hits, bouncing back from a rough start at Philadelphia. The right-hander was tagged for five runs and eight hits in five innings against the Phillies in his worst start of the season last Sunday.

Chicago has lost four in a row after a four-game winning streak.

Cubs right-hander Donn Roach (0-1) lasted just 3 1/3 innings in his first major league appearance of the year. He was charged with four runs and eight hits while subbing for Tsuyoshi Wada, who has a sore elbow.

The Cardinals scored four runs in the fourth and fifth. Heyward singled and scored on Yadier Molina's double in the fourth, and walked and scored on Randal Grichuk's double in the fifth.

Scruggs, Kolten Wong and Matt Carpenter each drove in two runs as St. Louis reached the 50-win mark before July for the first time in franchise history. Scruggs, who was promoted from Triple-A Memphis on June 19, gave the Cardinals the lead for good with a run-scoring single in the fourth.

In Friday's series opener, rookie Greg Garcia, also recalled from Memphis on June 19, connected for a tying pinch-hit homer in the eighth, and the Cardinals went on to a 3-2 victory in 10 innings.

"Greg, he's my man and it was great to see him contribute like that," Scruggs said. "Tonight, I just wanted to get out there and do something, too."

Heyward, who was 2 for 3 with two walks and scored twice, enjoyed seeing the rookies step up.

"It just makes you feel good to see the young guys do that," Heyward said. "It also shows the depth of this team that guys like that can come up, step in, and contribute right away."

Wacha retired his last six batters and seemed to pick up steam as he went along.

"The last couple innings, I felt really good," Wacha said. "It was a struggle the first few innings, a lot of stressful innings. But it was nice to have couple easy ones."

Carlos Villanueva pitched three innings of one-hit ball against his former team for his first save of the year.

Roach drove in Starlin Castro with an RBI single in the second. Castro has hit safely in his last 12 games against St. Louis.

Roach set the Cardinals down in order in the third, but struggled in the fourth.

"I think they did a good job of staying up the middle," Roach said. "I obviously threw some mistakes today, but I didn't think it was that bad."

Chicago was 1 for 8 with runners in scoring position and is 2 for 17 in the series.

"No question, we had opportunities," Cubs manager Joe Maddon said. "We did a lot of good things early. We just have to do better. It's very simple."

NO CONTEST

St. Louis is 6-2 against Chicago this year, outscoring the Cubs 41-25. The Cardinals went 10-9 against the Cubs last year.

TRAINER'S ROOM

Cubs: OF Jorge Soler, who has been out since June 3 with a left ankle sprain, will likely start a minor league rehabilitation assignment early next week. Soler is on the 15-day disabled list.

Cardinals: LHP Jaime Garcia, who suffered a groin cramp running the bases in his last start, will not take his scheduled turn on Tuesday. He skipped a bullpen session Saturday and could return to the rotation as early as Wednesday. RHP Lance Lynn (5-4, 2.84 ERA) will start Tuesday.

UP NEXT

Cardinals RHP Carlos Martinez (8-3, 2.89 ERA) faces RHP Jason Hammel (5-2, 2.65 ERA) in the finale of the three-game series on Sunday night. Hammel has eight quality starts in his last 11 outings. The Cardinals are 11-3 in games started by Martinez this season.