(Reuters/Eddie Keogh)

Updated Oct. 22 at 2:50 p.m.

Novak Djokovic tweeted early Wednesday morning that his wife, Jelena, gave birth to the couple’s first child, a baby boy named Stefan.

A Tuesday night report by Serbia’s Novosti Online said that the pair’s families celebrated at the “Novak” restaurants and that Djokovic is “happy, proud and joyful.”

Djokovic, the world No. 1 tennis player, announced in April that he and then fiancee Jelena Ristic were expecting a baby but had been tight lipped about the due date, commenting in May that he had “been told not to say too much.”

The 27-year-old married Ristic in July, shortly after winning his second Wimbledon title, and his happiness in his personal life has translated into success on the tennis court.

Djokovic also reached the semifinal of the U.S. Open and has a 52-8 record so far this year.

He tweeted a photo of his first practice as a father Wednesday afternoon, as he prepares for the BNP Paribas Masters in Paris that starts next week.

(H/T Tennis X)