The defending champions are officially on the ropes.

The New York Liberty stunned the Chicago Sky with a 98-91 victory on the road in Game 1 of their first-round playoff series at Wintrust Arena on Wednesday. Since the first round is a best-of-three affair, Chicago will need to win two straight—including a decisive Game 3 on the road—to preserve its title defense.

It seemed as if the Sky would cruise to a victory with a 91-85 lead with less than four minutes remaining, but New York closed the game on a 13-0 run.

Sabrina Ionescu led the way with a three-pointer and pull-up during that sequence and finished with 22 points, seven rebounds, six assists and two steals behind 8-of-12 shooting from the field.

Her performance drew plenty of reaction:

Ionescu used her speed to push the pace and was a willing passer whenever Chicago trapped and doubled her. Yet it was far from a solo effort, as Natasha Howard poured in 22 points while playing strong, physical defense throughout the contest.

Stefanie Dolson was also a matchup problem with her ability to stretch the floor from the frontcourt and added 13 points and seven rebounds, while Betnijah Laney did a little bit of everything on her way to 17 points, six rebounds and five assists.

It was a rather shocking finish considering almost all of Chicago's star-studded roster seemed to be playing well for most of the game. Candace Parker, Courtney Vandersloot, Kahleah Copper and Azurá Stevens all impressed at times, and the veteran group looked well on the way to another clutch playoff performance.

And then the Sky collapsed down the stretch.

The Liberty will look to close the series out in Chicago in Game 2 on Saturday.