Adam Engel and Matt Davidson homered and the White Sox snapped a nine-game losing streak with a 3-1 victory over their crosstown rivals in their North Side ballpark on Monday.
Miguel Gonzalez (5-9) allowed one run and seven hits in 7 1/3 innings to end a four-game losing streak and win for just the second time in 11 decisions.
Engel lined his third homer of the season off reliever Justin Grimm (1-1) into the wind and several rows into the left-center bleachers to snap a 1-all tie in the sixth. Davidson led off the eighth with his 19th homer, which sailed over the left-field stands and onto Waveland Avenue.
Jose Abreu had two hits and doubled in a run for the AL-worst White Sox, who ended their longest slide in four years.
The Cubs lost for just the second time in 10 games following the All-Star break to fall a half-game behind idle first-place Milwaukee in the NL Central.
Monday's game was the first of four consecutive this week between the Cubs and White Sox.
In his first start since June 4 because of tendinitis in his pitching hand, Cubs right-hander Kyle Hendricks pitched 4 1/3 innings and allowed a run and eight hits.
Hendricks struck out five and walked none.
White Sox reliever Anthony Swarzak got four outs for his first career save in eight chances. After Kris Bryant's infield single and a walk to Anthony Rizzo with two outs in the ninth, he struck out Willson Contreras looking.
Jon Jay had four hits, including a double, for the Cubs, but they left 12 men on base.
Carlos Rodon (1-3, 5.75) makes his fifth start since returning from left biceps bursitis. The Cubs counter with righty John Lackey (6-9, 5.04) in the second game of the series, another matinee at Wrigley Field. Games 3 and 4 are at Guaranteed Rate Field and start at 7:10 p.m. local time.
>>Cardinals Beat Rockies
Randal Grichuk hit a two-run homer, Mike Leake pitched seven scoreless innings and the St. Louis Cardinals beat the Colorado Rockies 8-2 on Monday night.
Leake's six-strikeout performance was his best June 30.
Kevin Siegrist pitched the Cardinals out of a two-on, one-out jam in the eighth by getting Gerardo Parra to strike out and Mark Reynolds to fly out. Tyler Lyons struck out the side in the ninth.
The Cardinals improved to 20-5 against the Rockies at home since the 2010 season. Colorado fell to 3-14 in its last 17 road games.
Grichuk's two-run homer off Rockies starter Antonio Senzatela (10-4) gave the Cardinals a 4-0 lead in the fourth, extending his home run streak to a career-high four games. He is the 11th player in the major leagues to have such a streak this season.
Jose Martinez and Tommy Pham each hit solo home runs in the seventh off Chris Rusin to make it 6-0.
Senzatela lasted just four innings.
Pat Valaika's third career pinch-hit home run in the eighth was the Rockies' offense, as Zach Duke failed to record an out in relief of Leake.
Jon Gray (3-1, 6.19 ERA) allowed a career-high nine earned runs over 3 1/3 innings in his lone career start against St. Louis on May 19, 2016. He is 3-1 with a 7.32 ERA over his past four starts.
Lance Lynn (8-6, 3.30 ERA) has held opponents to two runs or less in 14 starts this season. He is 2-2 with a 2.97 ERA in six career starts against Colorado.
