MILWAUKEE (Interstat) — David Peterson pitched six innings of one-run ball and Ian Happ delivered a tiebreaking three-run homer in the sixth inning as the Chicago Cubs defeated the Milwaukee Brewers 8-2 on Saturday at American Family Field.

Peterson earned his fourth win of the season, improving to 4-6 after allowing one run on four hits over six innings. He struck out four and walked one. The left-hander was backed by an offense that pounded out nine hits and capitalized on six walks from Brewers pitching.

Milwaukee took an early lead when Jackson Chourio led off the bottom of the first inning with his 11th home run of the season, a line drive to center field off Cubs starter David Peterson. The Brewers held that 1-0 advantage into the fourth inning.

The Cubs answered in the top of the fourth. Matt Shaw led off with a single, and Seiya Suzuki followed by launching a 1-0 pitch over the right-field wall for his 12th homer, giving Chicago a 2-1 lead. Suzuki finished the game 2 for 5 with two RBIs.

Milwaukee tied the game in the fifth. Blake Perkins doubled to lead off the inning and scored on a single by Sal Frelick, knotting the score at 2-2.

The decisive inning came in the sixth. With one out, Alex Bregman walked and Michael Busch also walked, bringing up Nico Hoerner. Hoerner singled to right field, scoring Bregman and moving Busch to third. Happ then followed with his 17th homer, a fly ball to right field that cleared the wall and brought home Busch and Hoerner, making the score 6-2. Happ finished the game 1 for 4 with three RBIs.

The Cubs added a run in the seventh. Matt Shaw walked, Suzuki singled and Bregman lifted a sacrifice fly to left field, scoring Shaw. In the ninth, pinch hitter Michael Conforto hit a solo home run, his fifth of the season, to cap the scoring at 8-2.

Milwaukee’s only other scoring threat came in the second inning when Gary Sánchez singled, but he was erased on a forceout. The Brewers managed just one hit after the fifth inning, and their offense finished with five hits total.

Chad Patrick took the loss for Milwaukee, falling to 5-4. He allowed six runs on six hits over 5 2/3 innings, walking four and striking out five.

The Cubs bullpen was effective in relief. Jacob Webb threw a scoreless eighth inning with two strikeouts, and Vince Velasquez worked a perfect ninth with no hits allowed. Tyler Ferguson recorded one strikeout in a third of an inning of work.

Chicago’s defense also contributed. Shortstop Dansby Swanson and second baseman Nico Hoerner turned a double play in the fifth inning to end a Brewers threat.

The game was played before a crowd of 40,193 and lasted 2 hours, 32 minutes.

The Cubs improved to 44-38 with the win, while the Brewers fell to 50-30. Chicago had lost the series opener Friday night 6-2 but had won three of its previous four games. Milwaukee had won eight of its last 10 before Saturday.

The most important sequence of the game occurred in the top of the sixth inning. With the score tied 2-2, the Cubs loaded the bases on two walks and a single, and Happ’s three-run homer broke the tie and gave Chicago a four-run lead. That inning turned the game decisively in the Cubs’ favor, as the Brewers did not mount another serious threat.

Peterson retired 10 of the final 12 batters he faced after the fifth inning, and the Brewers did not advance a runner past first base after the fifth. Chicago’s bullpen retired all six batters it faced.

The Cubs will face the Brewers again Sunday in the series finale at American Family Field, with first pitch scheduled for 1:10 p.m. Chicago then returns home for a three-game series against the San Diego Padres beginning Monday. Milwaukee will host the Cincinnati Reds for a four-game series starting Monday.

The Interstat game simulator had projected a final score of Chicago Cubs 7, Milwaukee Brewers 6. Interstat’s ELO system had projected Milwaukee with a 60.40 percent probability to win. Milwaukee had been installed as a pregame favorite with a spread of minus 1.5. The total score of 10 went under the over/under line of 8.