CHICAGO - Jon Lester's first season with the Chicago Cubs is not going as planned.

Lester's winless streak stretched to seven starts when he lasted four innings in his shortest outing in more than three years, and the Los Angeles Dodgers beat the Chicago Cubs 4-0 Thursday for a four-game split.

Signed to a $155 million, six-year contract, Lester (4-6) allowed four runs, four hits and four walks, while striking out five. He is 0-4 with a 4.43 ERA since beating Pittsburgh on May 16.

"It just comes down to the things I keep preaching and harping on, is fastball location and executing pitches," Lester said. "That's what it comes down to, and I'm not doing it consistently enough right now to help this team."

Lester had not gotten that few outs in a start since lasting two-plus innings for Boston in an 18-3 loss to Texas on April 17, 2012.

When Lester was in the AL with Boston or Oakland, he was allowed to go longer in games on occasions when he gave up early runs. But with no designated hitter in the NL, the Cubs pinch hit for Lester in the fourth after he threw consecutive scoreless innings.

"There's been times where in my career I've given up four in the first and gotten into the eighth," Lester said. "That just doesn't happen here."

His frustration showed in the second inning after he walked A.J. Ellis. Lester said he turned around with his head down and yelled something to himself, but apparently plate umpire Andy Fletcher thought it was aimed at him, Fletcher had to be blocked from getting closer to the pitcher by catcher David Ross. Chicago manager Joe Maddon then came out to argue with Fletcher but was not ejected.

"Rossie did a great job of going out there and got between him, and I was able to talk to Andy and I think it settled down after that," Maddon said.

Carlos Frias combined with four relievers on an eight-hitter. Jimmy Rollins had two hits, an RBI and run scored for the NL West-leading Dodgers, who won the final two games of the series.

Left fielder Alex Guerrero threw out Chris Coghlan at home plate in the fourth inning when Coghlan tried to score from second on Miguel Montero's two-out single.

"Carlos put up zeroes through five and the bullpen did a nice job piecing it together for us," Dodgers manager Don Mattingly said.

Howie Kendrick hit a two-run double in the first, and Enrique Hernandez tripled in a run in the second.

Frias (5-5) allowed seven hits in five innings, struck out five and walked three. He had been 0-3 with a 5.25 ERA in 24 innings since winning at St. Louis on May 30. Joel Peralta, J.P. Howell, Yimi Garcia and Kenley Jansen pitched an inning each.

Frias was sick earlier this week and said he "didn't eat for like a day and a half" and got dehydrated.

"I couldn't go deep in the game, but I did my best," Frias said.

Lester, meanwhile, wasn't at his best again.

"I feel good going into starts," he said. "It's not like I'm searching for things."

TRAINER'S ROOM

Dodgers: OF Yasiel Puig didn't start for the second straight game because of an open callous on his left hand.

Cubs: LHP Tsuyoshi Wada (left shoulder) hasn't been ruled out of making a start Saturday against St. Louis, and the Cubs will announce their starter for that game Friday. ... Maddon said OF Jorge Soler (left ankle) is "relatively close" to being able to go on a rehab assignment.

UP NEXT

Dodgers: LHP Brett Anderson (3-4) faces Marlins LHP Justin Nicolino (1-0) on Friday in Miami.

Cubs: RHP Jake Arrieta (7-5) pitches against the Cardinals and RHP John Lackey (6-4) on Friday in St. Louis. Arrieta is 3-1 with a 1.51 ERA in seven starts against St. Louis.

LIMITED DAY

Chicago did not start Starlin Castro and played the last seven innings without Kris Bryant. The rookie struck out in the first, then left after the second inning with what the team called flu-like symptoms. Castro was a late scratch from the starting lineup because he was anticipating the birth of his second child, which was a daughter named Scarlett. He entered in the sixth as part of a double switch.