Retiring tennis dad's heartwarming moment with son after US Open loss

French tennis veteran Nicolas Mahut has shared a beautiful moment with his son after losing in the last round of US Open qualifying.

The 36-year-old Mahut, who is best known for taking part in the longest match in tennis history against John Isner at Wimbledon in 2010, is set to retire from singles competition at the end of the year.

A former world No.37, Mahut flagged the decision after losing in the first round of his home French Open earlier this year.

Having lost in qualifying at the Australian Open and Wimbledon, his crack at the US Open was likely his last hope at a grand slam.

But he was defeated by Spanish veteran Tommy Robredo in three sets on Saturday morning AEST – and reality seemed to sink in.

Mahut was sitting in his chair, leaning on his hand and contemplating the future, when he suddenly had a visitor.

His seven-year-old son Natanel rushed across the court and jumped into his dad’s arms for a consoling hug.

Mahut dug his head into his son’s shoulder and rubbed his back in a heartwarming embrace after what must have been a disappointing defeat.

Robredo, who is also 36 and on his last legs as a singles competitor, must have known he was close to going through those emotions.

The Spaniard crossed the net and offered Mahut and Natanel a handshake and a smile in a brilliant act of sportsmanship.

Mahut could still get into the US Open main draw as a lucky loser if a handful of players withdraw through injury.

If not, it’s another chapter in Natanel’s book of understanding his dad’s emotions.

After Mahut won the French Open doubles title with countryman Pierre-Hugues Herbert in June, the boy shared a celebratory hug and kiss with his dad – and his playing partner.