It may have been the last day of the regular season with the postseason firmly in sight, but the Reds still found ways to be tested, and pass.

A 5-3 victory in 10 innings over the Twins -- with Tucker Barnhart's RBI single as the go-ahead run -- gave Cincinnati a 31-29 regular-season record, its first winning season in seven years. A Cardinals win over the Brewers locked the Reds into the seventh seed for the National League postseason bracket and earned them a showdown with the Braves in the best-of-three Wild Card Series that will begin on Wednesday in Atlanta.

• Box score

"We wanted to finish the season over .500. We clawed to get back to .500 for so long through the course of these 60 games," Reds starter Sonny Gray said. "We knew going in, the importance of this game was minimal as far as making it to the playoffs with what you do and who you play and this and that. We wanted to do it for ourselves. We came with some energy, and we wanted to end this on a high note. That’s what we did today. It was a crazy, hard-fought game, and we were in it until the end."

On Sept. 12, the Reds were 20-26. They finished the season 11-3 and won five consecutive series.

With one out and Michael Lorenzen on second base as an extra-inning pinch-runner, Curt Casali hit a single off Sergio Romo to center field. Lorenzen hesitated to see if the ball was caught, costing him a chance to score. Barnhart picked him up with his own single to score the first of three runs to cross in the inning, staking the Reds to their first lead of the day. Joey Votto's bases-loaded walk from Romo and Eugenio Suárez's RBI single added the others.

"From my experience in the playoffs, momentum is everything," said second baseman Kyle Farmer, who turned a huge double play to save a run in the fourth inning. “The way we finished, winning the series -- the momentum is huge, especially in the playoffs. Hottest team always wins. I think we feel a lot better winning our last game than losing. Momentum's huge. As long as we keep rolling, our pitching staff stays hot, our hitters stay hot, we're going to be in good shape."

A team that scored 62.5 percent of its runs via homers entering the day, the Reds scored all of their runs Sunday without a long ball.

"Everyone contributed. It was a fun game," Reds manager David Bell said. "Maybe it wouldn't have changed anything, we’re headed to Atlanta. But it sure was nice to see everybody play well and finish the regular season really feeling good about themselves and feeling good about our team."

Gray pitched 5 1/3 innings and allowed two runs and only two hits with four walks and four strikeouts for a no-decision. He gave up three runs and four hits over his last two starts upon returning from the 10-day injured list after dealing with a right mid-back strain.

Up next for Gray is to pitch Game 3 of the Wild Card Series, if necessary, on Friday.

"Physically, I feel great with where I’m at going into this next start, this next series," Gray said. "If it comes, great. If not, hopefully we’re moving on and going to other things. I feel good. I feel like I’m in a really, really good spot moving forward. It was nice to get back out there and get another start and keep going.”

The Twins, which clinched the American League Central on Sunday, are one of the toughest teams to face at home, with a 24-7 record at Target Field.

"It was important, obviously coming in here, we had to have a good series," Bell said. "Everything shifted a little bit, changed a little bit after Friday night. But even last night, we lost, I was really happy with the way our team and each and every player responded."