Novak Djokovic, the world's top-ranked tennis player, announced via social media on Wednesday that he was engaged to marry his longtime girlfriend, Jelena Ristic.

"Meet my fiance (sic) and future wife," Djokovic, 26, said in a tweet that linked to a photo of the Serbian-born tennis star being kissed by his fiancee, also a Serb. "So happy! Thank you for the wonderful wishes #NoleFam and friends!"

Ristic is well-known to tennis fans as a fashionable and enthusiastic presence at Djokovic's matches and is director of his charitable foundation.

Ristic and Andy Murray’s girlfriend Kim Sears emerged as the queens of Centre court at Wimbledon this year, the glamour duo living every point as their respective partners slugged it out.

Ristic lives with Djokovic and their pet poodle Pierre in Monte Carlo.