CHICAGO (Interstat) — The Chicago Cubs erupted for six runs in the first inning and rode the dominant pitching of David Peterson to an 11-2 victory over the Detroit Tigers on Tuesday, July 21, 2026, at Wrigley Field.

The Cubs improved to 57-44, while Detroit fell to 47-54. The game took 2 hours, 43 minutes before an announced crowd of 39,039.

Peterson, who entered with a 4-7 record, turned in his best start of the season. The left-hander allowed only three hits over 6 2/3 innings, did not yield an earned run and struck out four. He walked one and lowered his ERA significantly after coming off a loss at Baltimore on July 9 in which he gave up one earned run in five innings.

The Cubs offense provided immediate support. Leading off the bottom of the first, center fielder Pete Crow-Armstrong tripled to right field. Right fielder Seiya Suzuki walked. Third baseman Alex Bregman was hit by a pitch, loading the bases. Catcher Carson Kelly singled to right, driving in Crow-Armstrong and Suzuki, with Bregman advancing to third. First baseman Michael Busch singled sharply to right, scoring Bregman and sending Kelly to second. Second baseman Nico Hoerner singled to center, loading the bases again. Left fielder Ian Happ singled on a fly ball to second baseman Gleyber Torres, deflected by right fielder Ben Malgeri, scoring Kelly. Shortstop Dansby Swanson popped out for the first out. Right fielder Kevin Alcántara struck out. Crow-Armstrong then walked, forcing in Busch. Suzuki walked again, forcing in Hoerner. Bregman flied out to center, ending the inning with the Cubs leading 6-0.

The Cubs added a run in the third. Swanson walked, advanced on a strikeout, and scored on a single to right by Crow-Armstrong, who took second on the throw. The inning ended with the score 7-0.

Chicago extended the lead in the fifth. Swanson singled to right. Pinch-hitter Michael Conforto, batting for Alcántara, homered to right-center field, scoring Swanson and making it 9-0. Crow-Armstrong walked. Suzuki grounded into a double play, and Bregman grounded out.

The Cubs made it 11-0 in the seventh. Happ walked. Swanson singled, sending Happ to second. Conforto flied out, allowing Happ to advance to third. Crow-Armstrong walked to load the bases. Suzuki grounded into a force out, with Happ scoring and Swanson moving to third. Bregman singled to left, scoring Swanson. Kelly walked to re-load the bases, but Busch popped out.

Detroit’s only runs came in the ninth. With the Cubs leading 11-0, shortstop Hao-Yu Lee singled to center. Designated hitter Dillon Dingler homered to left-center field, his 22nd of the season, scoring Lee to cut the deficit to 11-2. The Tigers got a walk and a single but could not score again.

Peterson faced just three batters in the first inning, but after the Tigers’ first three batters were retired, the onslaught began. The key sequence was the six-run first, which included five singles, three walks, a hit batter and a triple, all before the Cubs recorded a second out. That inning effectively decided the game.

Detroit starter Framber Valdez took the loss, falling to 5-7. Valdez lasted only 2 1/3 innings, allowing seven earned runs on 10 hits and three walks with four strikeouts. The Tigers bullpen fared better, with Ty Madden throwing 3 1/3 innings of one-run ball, striking out five. Jake Rogers pitched a scoreless inning with two strikeouts, and Brenan Hanifee gave up two earned runs in two innings.

For the Cubs, Conforto hit his ninth homer of the season and drove in two. Crow-Armstrong had two hits and two RBIs. Carson Kelly went 1 for 3 with two RBIs. Alex Bregman had one hit and one RBI. Aaron Civale pitched the final 2 1/3 innings, allowing two earned runs on four hits with two strikeouts.

For Detroit, Dingler had the only extra-base hits, a double in the second and the two-run homer in the ninth. He finished 2 for 3 with a walk and two RBIs. The Tigers managed only seven hits total and struck out seven times.

The Tigers had won the previous game in the series, an 8-6, 10-inning victory Monday. That snapped a two-game losing streak for Detroit, which had lost three of its previous five. The Cubs had won five of their previous six before Tuesday.

The most important part of the game was the Cubs’ six-run first inning. The Tigers had no answer for Peterson, who retired 11 of the first 13 hitters he faced after the first. Detroit did not advance a runner past second base until the seventh, when Matt Vierling singled to put runners at the corners with two out, but a flyout ended the threat.

Interstat’s game simulator had projected a final score of Chicago Cubs 7, Detroit Tigers 6. Interstat’s ELO system gave the Cubs a 59.10 percent probability to win. Detroit was installed as a pregame favorite with a spread of -1.5. The total score of 13 went under the over/under line of 8.5.

The two teams conclude their series Wednesday before the Cubs travel to Pittsburgh for a weekend set. Detroit returns home to host Kansas City on Thursday.