Paula Badosa pulls off birthday prank on Aryna Sabalenka in Guadalajara

WATCH: Sabalenka and Badosa became doubles partners earlier this season and faced off in Stuttgart.

Are we witnessing the start of a WTA prank war?

Paula Badosa sent an opening salvo in Guadalajara on Monday when she tipped off restaurant staff that it was good friend Aryna Sabalenka’s birthday.

Only it wasn’t—the US Open semifinalist was born on May 5.

With the plan in action, Badosa captured the moment a baffled Sabalenka was confronted with a sparkler cake and presented a giant “S”-shaped balloon.

Sabalenka addressed the prank on Instagram later that evening, mischievously promising a “nice present” for Badosa in time for her November 15 birthday.

“This one was really funny,” Sabalenka wrote on her Instagram stories, “still can’t stop laughing.”

Badosa and Sabalenka faced off on court for the first time last summer in Cincinnati, but didn’t become friends until earlier this season when they agreed to play doubles together in Miami.

“I would say she’s like my soulmate on the tour,” Sabakenka said at the US Open. “I found that she’s pretty similar to me; we have the same character and reactions to things.

“If you look at her, you might think that she’s standoffish or self-involved, but she’s so different in reality!”