BOX SCORE

CHICAGO — The Cubs entered Sunday with a chance to win a series after dropping two straight sets.

Ian Happ helped deliver that with a walk-off, 10th-inning single as the Cubs beat the Pirates 3-2 on Sunday at Wrigley Field.

The Cubs (44-28) will enjoy their first day off in two weeks before opening a three-game series against the Milwaukee Brewers on Tuesday.

Here are three takeaways from the game:

Flexen their muscles

The Cubs bullpen has been nails – we’ll get to that in a second. But Chris Flexen has, in some ways, been a poster child for this reliever corps.

He was signed as a non-roster invitee to spring training, spent the beginning of the season with the Triple-A Iowa Cubs and was added to the big-league roster at the start of May. He pitched a perfect 10th inning on Sunday, stranding the extra innings runner. He has now pitched 18.1 innings for the Cubs without allowing an earned run.

Flexen exemplifies how the Cubs have built this bullpen. Their relievers are generally under-the-radar signings who have stepped up and played vital roles for this team. The Cubs have struggled scoring in extras – they had six runs scored in eight extra-inning games entering Sunday – so keeping the Pirates scoreless was a big help for the offense.

They needed just the one run, and Ian Happ delivered.

Rea’s Day

Colin Rea’s last three starts have been a struggle. He had allowed 16 runs in 15 innings (9.60 ERA) and had a 1.93 WHIP. The Cubs used an opener in his penultimate outing and that led to a successful appearance, with 5.1 scoreless innings with five hits allowed.

Sunday’s outing started out worrisome. He allowed three hits and a pair of runs within the first five hitters of the game. But Rea settled in after that and looked more like the pitcher who followed the opener on June 5 in Washington.

He recorded nine straight outs following a one-out single in the first and permitted just two base runners after the opening frame – a one-out walk in the fourth and a two-out single in the sixth.

That’s a big performance for this Cubs rotation. They’ve been down both Justin Steele and Shota Imanaga since May 5, and have posted a 4.32 ERA since the Japanese left-hander went down. That is the 19th-best mark in baseball over that time.

Rea was a strong contributor when he first joined the rotation but had struggled of late. He’s a key piece to the Cubs’ pitching staff, albeit not a flashy name, and having him contribute like he did Sunday is key.

Bullpen musings

The Cubs’ reliever corps has been good – that’s no secret. They sport an MLB-best 0.90 ERA since May 14 (100 innings) and a 3.21 ERA on the season, the fourth-best mark in baseball. Even still, that position group has been taxed.

This stretch of their schedule was always going to be a gauntlet. Sunday’s contest was their 13th in a row without a day off and the halfway point of a 26-games-in-27-days stretch. That’s difficult for a team, especially their bullpen.

Daniel Palencia picked up the save on Saturday his third straight day pitching. Drew Pomeranz recorded a hold in that game, pitching on back-to-back days and in his third appearance in four days. Brad Keller had pitched four times in five days before not being used on Saturday.

That meant Cubs manager Craig Counsell had some limited choices late in game. Palencia, Keller and Pomeranz were not used in Sunday’s contest as Counsell was always likely to avoid them to provide a pair of days off in a row.

It allowed someone like Génesis Cabrera to be used in a leverage spot. He pitched the eighth inning of a tie ball game. The left-hander threw a scoreless inning, working around a leadoff walk by picking up an inning-ending double play.

He’s an interesting name for the Cubs’ bullpen. They’re carrying three lefties, a rare thing to do in a bullpen, but he has been solid for a group that has been really good. His 2.84 ERA is strong but, in this ‘pen, though, it’s relatively high. That’s how deep that group is.

That’s a good thing for the Cubs.