Sylvia Fowles made sure the Chicago Sky didn't pay for a sluggish start Sunday.

Fowles had 20 points and 21 rebounds to help the East-leading Sky rally from a 25-point deficit for an 89-78 victory over the Connecticut Sun.

Connecticut scored the game's first 15 points, capped by a desperation 3-pointer by Renee Montgomery with 4:35 left to beat the 24-second shot clock. Montgomery's layup with 1:58 remaining in the first half gave the Sun a 43-18 lead.

But the Sky outscored Connecticut 62-35 in the second half, taking their first lead with 2:48 left in the game on Epiphanny Prince's three-point play. That undid a first half in which Connecticut outscored the Sky 43-27 and shot 48.5 percent from the floor.

"Extremely frustrated," Connecticut coach Anne Donovan said. "We had a great 20 minutes in the first half playing good defense, scoring off of our defense. And in the second half — give credit to Chicago, they came out ran better offense, got more aggressive offensively. And 62 points in a half is pretty amazing."

Chicago added to its lead to win for the fourth time in five games and sweep the four-game season series from Connecticut. The Sky are also closing in on the franchise's first playoff berth and clinched their first non-losing season.

"It's one of those things where you can't be minus-25," Sky coach Pokey Chatman said. "We were fortunate, but at least I can take some true basketball clips that were from some blue-collar areas of the game — defense, deflections, rebounding, getting out in transition — that got us to the win."

The Sky (17-8) were without Elena Delle Donne for the second straight game. The rookie star is day to day with a left foot she sprained Tuesday in Los Angeles.

Chatman said Delle Donne, who's averaging 18.2 points per game, could play Tuesday at Washington. Chicago's first two games without Delle Donne have had similar stories.

Thursday in Seattle, the Sky trailed by as many as 16 points but came back to beat the Storm 79-66, with Prince scoring 12 in the fourth quarter. On Sunday, Chicago outscored Connecticut 38-20 in the fourth to seal the victory, as the Sky ended the game on a 25-5 run.

Fowles didn't seem to think one had an impact on the other.

"You can't think about the last game. The last game's the last game" Fowles said. "Our focus was to go out there and not make the mistakes we made in the first half."

Chicago committed 11 turnovers in the first half while shooting 10 of 34 (29.4 percent) from the floor.

The second was different, and Chicago had another comeback win.

"I think it shows a lot of character," said Prince, who led the Sky with 21 points, 19 of them coming in the second half. "When our backs are against the wall we don't quit."

Having Fowles didn't hurt.

Her 20 points and 21 rebounds gave her a second 20/20 game this season and the second in team history, with the first coming against Connecticut on May 31.

In four games against Connecticut, Fowles averaged 18 points and 15.3 rebounds.

"I thought my teammates did a great job helping me down there," Connecticut center Tina Charles said. "That's what she's capable of doing. She can do that every night if she wants to."

For now, Fowles doesn't seem too interested in the numbers she's racking up. Or if she is, she isn't saying it.

"I haven't sat back and thought about it," Fowles said. "But, just to think about how I got it done I think is pretty impressive."

Tan White scored 16 points for Connecticut (7-17), which has lost five of six.