CHICAGO — Dansby Swanson hit two of Chicago’s five home runs and the Cubs held on for their fourth straight victory, 9-7 over the San Diego Padres on Tuesday night.Alex Bregman, Michael Busch and Pete Crow-Armstrong added homers to help the Cubs win for the 10th time in 12 games.Fernando Tatis Jr. hit two home runs and Manny Machado and Gavin Sheets also went deep as San Diego dropped its fourth straight after a four-game winning streak.Swanson hit a solo home run off JP Sears (1-1) in the second to give the Cubs the lead for good, then added a two-run shot off Ron Marinaccio in the fifth. He finished 3 for 4 with his second multi-homer game in less than a week — he hit two in the opening game of a doubleheader at the New York Mets on June 24.Javier Assad gave up Sheets’ three-run homer and Tatis’ second solo shot in the eighth to make it a two-run game, but the Padres couldn’t get closer. Ryan Rolison got the final out for his first save.Matthew Boyd (3-1) gave up both San Diego home …