CHICAGO (AP) -- Joe Maddon wants the Chicago Cubs to prove they can beat the best. Well, how's this for evidence?
The Cubs won the opener 7-4 behind a strong start by Jake Arrieta, then came back late in the nightcap. That gave Chicago its first doubleheader sweep against the Cardinals since June 8, 1992, at St. Louis - and their first at Wrigley Field since Oct. 5, 1991.
''We're here to win,'' Maddon said. ''It's not just to compete.''
Chicago scored three in the seventh to grab a 4-2 lead. Seth Maness (3-1) got ejected after giving up the tying single and replacement Kevin Siegrist threw away a grounder and allowed two more runs, as the Cubs beat the NL Central leaders for just the fourth time in 12 games.
Jason Motte gave up an RBI single to pinch-hitter Tony Cruz in the ninth. But he escaped with his fifth save in as many chances after Matt Carpenter fouled out and Jhonny Peralta grounded into a force to end the game.
Down 2-1, Chicago had runners on first and second with one out in the seventh when Russell hit an RBI single just inside the first base line.
As first base umpire Pat Hoberg called a fair ball, first baseman Mark Reynolds threw his arms up. Maness ran over and was tossed.
''I saw it hit two foot foul right in the dirt and it's really hard to see whereabouts it hit foul again,'' Maness said. ''I'm really no physics major, but I don't know how it hits foul and then curves back - but it could - I'm not saying it didn't.''
Asked about Russell's hit, Maddon said unconvincingly: ''It was a fair ball.''
Fair or foul, this much was clear.
''(Russell has) been struggling a lot and he did not cave. He did not quit,'' Maddon said.
Siegrist came in, fielded Dexter Fowler's comebacker and threw the ball into center field, trying for a forceout at second. That allowed Jonathan Herrera to score from third, and Anthony Rizzo had a sacrifice fly that made it 4-2.
The Cardinals scored two in the sixth to take a 2-1 lead while chasing out Dallas Beeler. The right-hander left to loud cheers with a 1-0 lead and runners on first and third.
Jason Heyward had an RBI grounder and Mark Reynolds drove him in with an infield hit.
Beeler was charged with two runs over five-plus innings. He gave up four hits, struck out six and walked two after being called up from the minors as the 26th man.
Rookie Tim Cooney, making his third start, allowed one run and three hits over 5 1-3 innings for St. Louis.
In the opener, Arrieta (9-5) pitched into the seventh inning and also got a career-high two hits.
Rizzo launched his 16th homer, a two-run drive off Randy Choate that highlighted a four-run eighth after St. Louis pulled within one.
Arrieta gave up two runs and seven hits in 6 2-3 innings and improved to 3-0 in his past four starts. He contributed a pair of singles and scored a run after starting the season 1 for 33.
Chris Denorfia had two hits and drove in three runs, knocking in two with a single in the third off Tyler Lyons (2-1).
''We have a good ballclub,'' Motte said. ''We showed it today by hanging in there, guys making nice plays and guys battling.''
Rizzo set a modern franchise record in the first inning of the second game when he was hit by a pitch for the 18th time.
Cardinals: 2B Kolten Wong was held out of the second game after banging his head in the opener. Wong was woozy after he sprawled out to catch a fly by Miguel Montero in shallow right field in the fifth inning. He was slow to get up and was replaced in the seventh. With Wong out of the lineup for the late game, Carpenter made his first start at second since 2013.
Cubs: Maddon said he got a good report on RHP Rafael Soriano, who struck out three in an inning of relief Monday for Double-A Tennessee - his first appearance for the organization. Soriano, who has 207 career saves, signed last month and had to wait for his immigration paperwork to go through before coming to the United States from the Dominican Republic.
All-Star Michael Wacha (10-3, 2.66) starts for St. Louis while RHP Jason Hammel (4-5, 2.89) pitches for Chicago.