CHICAGO -- Reds ace Johnny Cueto's goal of reaching 20 victories was still alive, but that was secondary to just having a good start.
A loser of three straight starts coming in, Cueto pitched six scoreless innings for his 18th victory as the Reds earned a 5-3 win for a series sweep over the Cubs.
"I was more relaxed," Cueto said through an interpreter. "I was concentrating more today and used the fastball more today. I felt good, like always. I always feel good."
Cincinnati became the first team in baseball to clinch a Wild Card playoff berth and lowered its magic number to clinch the National League Central to two after the Cardinals swept the Astros.
At 91-59, the Reds are 32 games over .500 for the first time since 1999, and they can clinch the division with a win over the Dodgers on Friday, combined with a Cardinals loss to the Cubs.
Cueto -- who gave up five hits with four walks and struck out a pair to reach a new career high for a season with 159 K's -- likely had lost his bid for a NL Cy Young Award by going 0-3 with an 8.22 ERA in his previous three starts. The win improved his record to 18-9 with a 2.84 ERA over a career-high 203 innings. He is tied for second in the league in wins and fourth in ERA.
There was danger to dodge on a few occasions vs. Chicago for Cueto. He allowed two hits and two walks and, even after a successful pickoff, loaded the bases during a 27-pitch second inning. In the fourth, after giving up Starlin Castro's leadoff triple, Cueto still kept Chicago off of the scoreboard.
"I don't think that was the best stuff he's ever had," Cubs manager Dale Sveum said. "You could tell he might be getting a little tired at the end of the year. I've seen him with better stuff."
With the game in a scoreless tie in the fourth, acting manager Chris Speier refused to concede the early run and played his infield in. Cueto got Luis Valbuena to ground out to second base and Welington Castillo to hit a shallow fly to left field. After a two-out walk, Cueto got pitcher Jason Berken to ground out.
"I gambled a little bit with a tie score and played the infield in," said Speier, who was standing in for the ailing Dusty Baker. "With Johnny, we haven't scored a lot with him. I didn't want to give them any opportunity to get any runs. We loved that Johnny pitched his way out of it."
Using a lineup of mainly bench players and September callups, while regulars were rested, the Reds were held scoreless for six innings with only two hits against Berken. They struck out four times in the second -- Ryan Hanigan reached on a wild pitch to prolong the inning -- making Berken the fifth Cubs pitcher to achieve the feat.
The Cubs turned to Manuel Corpas for the seventh, and the Reds' bats came alive while sending nine men to the plate. Denis Phipps -- who earned his first Major League hit, an infield single with one out -- was the first of five straight batters to notch a hit. Phipps later scored on Didi Gregorius' RBI single to right field.
Even though he had only 92 pitches, Speier decided to capitalize on the rally by pulling Cueto for pinch-hitter Joey Votto.
"I was really thinking of him wanting to go back out. I got greedy," said Speier, who is 6-0 in games as acting manager for the Reds since 2008. "But it worked out well. From Johnny's side, you can take away that he threw the ball really well."
It worked, as Votto notched his fourth RBI in two games with a single to left field that scored Hanigan. Xavier Paul added an RBI single to right field that scored Gregorius. With two outs, Henry Rodriguez laced a double to the gap in left-center field that scored two more runs, his first two big league RBIs, and made it a 5-0 game.
"A lot of guys had very good games, and they're the reason we're going to leave Chicago with a sweep," Votto said.
As for Cueto, coming out early didn't hurt as the Reds try to preserve his arm for the postseason. In all likelihood, the Reds will turn to him for Game 1 of the NL Division Series vs. a yet to be known opponent.
"They haven't said yet," Cueto said. "I believe I may be the one, because they moved [Bronson] Arroyo so the rotation would fit into that."
Chicago scored a run in the bottom of the seventh. After reliever Jose Arredondo issued a one-out walk and a single, Anthony Rizzo rolled an RBI single through the right side against lefty Sean Marshall. In the eighth, with two outs, Castillo hit a homer to left field off of Logan Ondrusek. And in the ninth, with Jonathan Broxton not available, Alfredo Simon gave up one run but held on for his first save, becoming the seventh Reds reliever to notch one this season.
With two starts remaining, Cueto can still become the first Reds pitcher since Danny Jackson in 1988 to achieve 20 wins. He next pitches on Wednesday vs. the Brewers.
"That's the goal. I want to keep working like I'm working," Cueto said. "There are two more games to go. I'm going to keep working as I've been doing it."