BOSTON -- The opportunities are dwindling for the Red Sox, and the completion of a three-game sweep of the White Sox was one they badly wanted to cash in on.

But they couldn’t finish the job on Sunday afternoon.

Instead, the 33-111 White Sox snapped a tie with a five-run rally against Zack Kelly in the top of the ninth and defeated Boston, 7-2, to salvage the finale of a three-game series at Fenway Park.

“We had a chance, right? And it was a tie game in the ninth, so we just didn't finish that inning,” said Red Sox manager Alex Cora.

The Twins were swept in Kansas City this weekend, so the Red Sox remained four games behind Minnesota in the race for the third American League Wild Card spot.

Though Cora’s club has lost six of eight, seven of 10 and 13 of 20, it is determined to stay in range of the Twins, who come to Fenway for a three-game series from Sept. 20-22.

While Boston's starting pitching has rebounded nicely, the offense, bullpen and defense continue to be trouble spots.

With the Orioles coming to town for a three-game series that starts Monday followed by a four-game series in New York against the Yankees, the execution of the Red Sox is going to need to improve in short order.

“We’ve got Baltimore and the Yankees, so we’ve just got to be ready to play,” Cora said. “We’ve got to play better.”

A day that started with the excitement of the club’s No. 13 prospect Richard Fitts making his Major League debut and turning in a solid performance (5 2/3 innings, six hits, two unearned runs, two strikeouts) ended in disappointment, as the Red Sox couldn’t generate enough offense to complete a sweep against the team with the worst record in MLB.

Boston was 0-for-6 with runners in scoring position.

“We didn't do much today offensively,” Cora said. “They put the ball in play, found some holes, and obviously, the ninth inning, that happened. But offensively, we didn't do much. It’s a tough one."

Aside from a solo homer by Connor Wong that put the Red Sox ahead in the second and an equalizing solo shot by Wilyer Abreu in the sixth, Boston couldn't do anything substantial at the plate.

Fitts -- the most highly touted of the three pitchers the Red Sox acquired for Alex Verdugo on Dec. 5 -- did his best to put his team in the win column.

“Today was really special, just because I got to share it with my family,” Fitts said. “I’m really honored to be a Red Sox today, and hopefully for a long time. The first pitch, I was trying to throw it as hard as I can in the zone. And after he just fouls it back, I’m like, ‘OK I’m a big leaguer, I deserve to be here. And I’m going to do everything I can to help the team win.”’

Fitts' solid work was undone in the sixth inning. Two runs by the White Sox in that frame changed the momentum of the game. They were the result of a costly fielding error by Triston Casas to lead off the inning, at which time Boston was clinging to a 1-0 lead.

“Hard hit,” Casas said. “It hit the grass and then popped up, and I anticipated the next hop being just as high, and it just stayed down. If you look at the high-home camera, you could tell as soon as it hit the ground, it popped up. Once it is hit at 103 [mph] and it pops up and you see the ball come up, you don’t anticipate it staying down once it hits the dirt. It typically hits that dirt and takes another top-spin higher. That was just what happened.”

Down, 2-1, with two outs in the bottom of the sixth, Boston answered swiftly when Abreu mashed his solo homer into the bleachers in right-center.

But the White Sox seized the momentum in the top of the ninth with their surge against Kelly.

“We knew September was going to be a dogfight, but we’re right where we want to be,” Casas said. “We have our backs against the wall and we have to play well for sure, but that just puts that much more focus on these types of games. It’s going to take the little things to come out with wins. We’re going to do things right, slow things down and play our style game.”