CHICAGO -- Reliever Seth Maness could not believe Addison Russell's tying single was called fair, and Cardinals manager Mike Matheny would have loved to challenge the play.
Instead, his pitcher was ejected, and the Cubs tacked on two more runs in the inning and beat St. Louis 5-3 on Tuesday to sweep the Cardinals in a doubleheader for the first time in 23 years.
"I saw it hit 2 feet 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."
The Cubs won the opener 7-4 behind a strong start by Jake Arrieta, then came back late in the nightcap. It gave Chicago its first doubleheader sweep against the Cardinals since June 8, 1992, at St. Louis -- and its first at Wrigley Field since Oct. 5, 1991.
Chicago scored three in the seventh to grab a 4-2 lead. Maness (3-1) was ejected after giving up the tying single, and replacement Kevin Siegrist threw away a grounder, allowing two more runs, as the Cubs beat the National League Central leaders for just the fourth time in 12 games.
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.
Matheny saw "two players over there screaming and yelling that it's a blatant miss" and went out to argue. He said he understood it wasn't a challengeable play but believes it should be.
"We have enough technology to show us. Why not take a look?" Matheny said. "We're taking a look at everything else."
Asked about Russell's hit, Cubs manager Joe Maddon said unconvincingly: "It was a fair ball."
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.
Chicago got another run in the eighth when Jorge Soler doubled and Starlin Castro drove him in with a sacrifice fly.
Pinch hitter Tony Cruz hit an RBI single for St. Louis in the ninth.
The Associated Press contributed to this report.