CINCINNATI -- With one more victory in a September that has been full of them, the Brewers get to play in October.

Lorenzo Cain is the optimistic sort, even while fighting through hand, knee and ankle injuries, but after watching National League Most Valuable Player Award candidate Christian Yelich go down with a crack in his kneecap, not even Cain saw this coming.

“It’s just like last September,” Cain said Tuesday, after a 4-2 win over the Reds put champagne on ice at Great American Ball Park. “I definitely didn’t expect it, but this team will surprise you. We’ve got a bunch of hard workers, guys that never quit. Now that we’re doing it and we’re on this run, we might as well keep it going, you know?”

• Box score

Ryan Braun hit his 27th career home run at GABP to extend his all-time record for a visitor, Cain and Ben Gamel made late-inning defensive saves, and Adrian Houser, Brent Suter, Drew Pomeranz and Josh Hader combined to pitch the Brewers' fifth win in a row, ninth in 10 games and 16th in 18 contests. As Milwaukee was locking down the victory, the Cubs were committing five errors in a seventh straight loss.

With that combination, the Brewers' magic number to clinch a spot in the postseason is down to one.

• MLB standings

That means with a Brewers victory on Wednesday, they are at worst the NL’s second Wild Card entrant. If Milwaukee loses, it could also clinch if the Cubs and Mets both fall.

“I’m hoping it happens [Wednesday],” Suter said. “But we’ve got to get a win.”

The Reds are hoping to keep their visitors' clubhouse carpet dry, and they were off to a solid start with a pair of first-inning runs against Houser. But Braun answered in the second inning with a solo homer off Sonny Gray, and the Brewers pushed ahead in the third on Yasmani Grandal’s RBI double and rookie Keston Hiura’s sacrifice fly. Houser then kept the Reds at bay through the fourth, Suter followed with three scoreless innings, and lefties Pomeranz and Hader took it the rest of the way.

That’s been the formula for the Brewers for most of a remarkable September run: Just enough offense to supplement sensational pitching. Since rosters expanded at the start of the month, Milwaukee has the best ERA in baseball (2.77) along with the best record (18-4). Since Yelich fractured his right kneecap on Sept. 10 and was lost for the season, the Brewers have an MLB-best 2.52 ERA and are 12-2.

“The story was, our pitching was excellent again,” Brewers manager Craig Counsell said.

It has been excellent for a while, particularly the three left-handers who combined to cover the final five innings. Suter, a September callup who is coming off Tommy John surgery, has allowed one run in 17 1/3 innings this month while holding hitters to a .150 average. Pomeranz, added at the July 31 Trade Deadline, is unscored upon in 17 of his last 18 appearances. Hader has 28 strikeouts in his last 16 2/3 innings and is unscored upon in 12 of his last 13 games.

Last season, it was Hader and right-handers Corey Knebel and Jeremy Jeffress down the stretch. This year, it’s a trio of lefties.

“Yeah, I thought about that,” Counsell said. “I mean, I don’t think we’ve ever done that before here in the bullpen. Those are our guys who are throwing the ball exceptionally well. They really are. Those are our guys who are hot right now. You roll with them.”

• How Brewers might pitch potential Wild Card Game

Suter has been the Brewers’ September surprise, considering his long layoff. He was so efficient and effective on Tuesday that Counsell let Suter bat in the seventh before pitching a third inning. The frame ended with Cain making a terrific running catch in the right-center-field gap.

“I don’t know what to say. It’s more than we could have ever thought,” Counsell said of Suter’s work. “It’s soft contact. Tonight, we got some baserunners, but it wasn’t hard-hit balls. It was balls in front of the outfielders. He’s doing his thing, and he keeps doing it, and he’s doing it very well. He’s really serving a role that we used Josh in last year, of controlling the middle of the games.”

With Suter probably unavailable due to the extended outing, someone else will have to handle that responsibility on Wednesday, when the Brewers will try to punch their postseason ticket.

Even if they do, there will be work ahead of them, because the NL Central crown has yet to be claimed. The Brewers did receive some good news on Tuesday when the D-backs beat the Cardinals in extra innings, narrowing Milwaukee’s deficit in the division to 2 1/2 games.

In the NL Wild Card standings, the Brewers remained one game behind the Nationals for the right to host the NL Wild Card Game next Tuesday night, after the Nats swept their doubleheader against the Phillies.

While those races go on, the clinch was as close as a day away.

“Oh, is it one day away? OK, OK. All right,” Cain said. “You pay attention, but at the same time, you handle your business. That’s the biggest thing. We’ve been handling our business. We’ve been doing our part. We have a chance to come here, show up and find a way to get a win. We didn’t swing the bats as well as we wanted to tonight, but we did just enough. Hader came in and finished the job as usual. We have to continue to do this, continue to play hard and focus and find a way to squeak out wins.”