Lois Boisson has fired back with humour after British tennis rival Harriet Dart complained on court about her body odour.

The French tennis player posted a photoshopped snap of herself mid-serve clutching a deodorant can and tagging Dove for a "much-needed collab."

Dart has since apologised for blurting out her opponent "smells really bad" during her heavy defeat at the Rouen Open on Tuesday.

Dart, who lost 6-0 6-3, was captured on the broadcast asking the umpire to tell Boisson to use deodorant, during a second-set changeover.

"Can you ask her to put on deodorant? She smells really bad," Dart was heard saying to the official as she struggled against the 21-year-old in the first round.

The comment sparked an immediate backlash on social media, prompting Dart to address the incident on Instagram.

"It was a comment made in the heat of the moment and I truly regret it. It's not the way I want to behave and I take full responsibility," Dart wrote.

"I have a lot of respect for Lois and the way she competed today. I'll learn from this and move on."

Meanwhile, Australian firebrand tennis star Nick Kyrgios, no stranger to controversy himself, weighed in saying: "Nah saying this when you are down and getting snipped is wild".

Boisson, who was already out on court while Dart was still seated, appeared to be out of earshot when the Briton made her remark.

The victory marked a stunning upset for the 303rd-ranked Boisson, making her first WTA Tour appearance of the season following injury, against the 62nd-ranked Dart, who failed to convert any of her six break points and dropped her serve four times.

The Women's Tennis Association (WTA) did not immediately respond to a Reuters request for comment.