Martina Navratilova reacted to Garbine Muguruza's French Open triumph by declaring "a new star is born", but insists the Spaniard's victory over Serena Williams does not represent a changing of the guard in women's tennis.
At the age of 22, Muguruza claimed her maiden grand-slam title on Saturday with a 7-5 6-4 victory over Williams on Court Philippe Chatrier.
Williams held all four slam singles crowns after beating Muguruza in last year's Wimbledon final.
However, after seeing the US Open and Australian Open titles slip from her grasp courtesy of shock defeats to Roberta Vinci and Angelique Kerber respectively, the world number one has now come up narrowly short at three successive major tournaments.
Nevertheless, Navratilova rejected the notion that Williams' time as the game's leading player was coming to an end.
Asked on ITV if there had been a changing of the guard, the nine-time Wimbledon singles champion replied: "Not yet. Serena Williams is still number one in the world.
"It's not a changing of the guard but a new star is born and now Serena Williams has a bona fide contender and opponent.
"Now Garbine Muguruza is a grand slam champion. Most of all, I love the way she did it, with style. She held her nerve."
Navratilova appears excited by the prospect of further battles between Muguruza and a player 12 years her senior.
She added: "Serena just hasn't had a rival, she hasn't had the competition. People haven't stepped up to the plate. Garbine Muguruza is a bona fide contender."
Muguruza's compatriot Rafael Nadal, a nine-time champion on the Roland Garros clay, tweeted a message of congratulations to the newest grand slam winner.
"Congrats Garbine for your win at Roland Garros," wrote Nadal. "Great news for Spanish tennis!"