CINCINNATI -- Anthony DeSclafani became the Cincinnati Reds' ace by default.
His season ended on a sour note Wednesday night.
The Reds lost their 11th straight, equaling their longest losing streak since dropping 12 consecutive in 1993, and DeSclafani took the defeat in his final start as Cincinnati fell 10-3 to the Chicago Cubs.
"We know it's ugly right now, and it doesn't even look like baseball," Reds manager Bryan Price said. "There is no satisfaction from playing this poorly. These guys have to get through this and get better. We want to get back to the playoffs with this group."
The Reds (63-95) play their last home game of the season at 12:35 p.m. against the Cubs, then finish with three games at Pittsburgh.
DeSclafani (9-13) allowed 14 runs in his last 15 2-3 innings over three straight losses. With Johnny Cueto and Mike Leake traded midseason, the 24-year-old DeSclafani led the staff in starts (31), wins and innings (184 2-3) in his first full campaign.
"He has been the saving grace for our staff," Price said. "We think the world of this kid. It was important to him and all these guys to get through September. "
Austin Jackson drove in a career-high five runs and Jon Lester set a Chicago season record for strikeouts by a left-handed pitcher, leading the playoff-bound Cubs to their fourth straight win.
The Cubs will play the Pirates in next week's NL wild-card game, as St. Louis clinched the NL Central Wednesday.
Lester's strikeout of Ivan De Jesus Jr. in the fifth inning was his 203rd of the season, snapping the franchise record for a left-hander set by Ken Holtzman in 1970. Lester (11-12) finished with nine strikeouts and retired the last 20 batters he faced.
Starlin Castro homered and had four hits for Chicago.
The Cubs reached double figures in runs for the first time since a 14-5 win over Arizona on Sept. 4.
Anthony Rizzo doubled to lead off the fourth, snapping a 0-for-11 slump, and scored on Addison Russell's single. In the fifth, Jackson followed Lester's leadoff single with a one-out RBI double.
Jackson added a bases-loaded two-run single in Chicago's three-run eighth.
Castro led off the sixth with his 11th homer of the season, helping knock DeSclafani out of the game.
"I guess it's been a good season overall," DeSclafani said. "I'm not happy with the way it ended. I had a couple goals in mind that I didn't reach."
With Todd Frazier and Joey Votto sidelined with minor injuries, the Reds scored their only runs on two Jay Bruce sacrifice flies and one by Brandon Phillips.
Reds: 3B Frazier was scratched from the starting lineup with stiffness in his lower right calf and Achilles tendon that developed after his foot caught in the grass while he tried to make a sliding catch of a foul ball Tuesday. 1B Votto was sidelined with stiffness in the back of his shoulders.
Cubs: RHP Jason Hammel (9-7) will try to reverse a season-ending performance dip in the series finale against the Reds. He is 4-3 over his last 12 starts with a 5.84 ERA.
Reds: LHP John Lamb (1-4) makes his 10th career start and first against the Cubs in Cincinnati's home finale.
The Reds' 1-0 lead in the first inning was their first advantage since they led the Mets 1-0 last Thursday. Cincinnati lost that game 6-4.
Tyler Holt, who was claimed on waivers by the Reds on Sunday from Cleveland, had a hit and scored a run in his first start as a Red. "Our scouts said that he is a high-energy guy who can find his way on this team," Price said.