Dansby Swanson went 3-for-4 with a pair of RBIs, while Ian Happ and Carson Kelly each homered, propelling the Chicago Cubs to a 9-2 victory over the visiting San Francisco Giants on Monday.

Happ drove in three runs and Seiya Suzuki drove in two, as the Cubs won their fourth game in five tries. Matthew Boyd (3-2) threw six innings of five-hit, two-run ball, while striking out seven for Chicago.

Landen Roupp (2-3) surrendered five hits and four runs (two earned) across five innings and struck out four. Luis Matos’ two-run homer accounted for all of the Giants’ offense, and San Francisco’s defense committed four errors. The Giants saw their three-game winning streak snapped.

Chicago struck first in the home half of the third, as Happ followed Swanson’s leadoff double with his third home run of the year — a 383-foot, two run-shot — giving the Cubs a 2-0 lead.

Jung Hoo Lee began the fourth with a single, before Boyd induced consecutive groundouts. Matos then launched his third home run of the season, knotting the game at two apiece.

After Roupp struck out Michael Busch and Kelly to begin the bottom of the fourth, Pete Crow-Armstrong reached on third baseman Matt Chapman’s fielding error, followed by Nico Hoerner’s single and Swanson’s two-run single.

Hayden Birdsong relieved Roupp in the sixth, surrendering Kelly’s solo homer, before Crow-Armstrong singled and Hoerner and Swanson both reached on errors, loading the bases with nobody out. Birdsong then walked Nicky Lopez and allowed Happ’s sac fly, giving the Cubs a 7-2 lead.

Birdsong’s disastrous inning continued when he issued a walk to Kyle Tucker. Spencer Bivens replaced Birdsong, giving up Suzuki’s two-run single, extending the Giants’ deficit to 9-2.

Caleb Thielbar replaced Boyd in the seventh, throwing a perfect inning in relief.

Gavin Hollowell then relieved Thielbar, retiring all three batters he faced in the eighth. Hollowell remained in for the ninth, working around Wilmer Flores’ one-out single to secure the Cubs’ victory.