Steffi Graf has heaped praise on Serena Williams after the American equalled her Open Era record of winning 22 Grand Slam titles.

Williams overcame Angelique Kerber 7-5 6-3 on Centre Court yesterday to match Graf's mark, as well as levelling up with the German on seven Wimbledon titles.

Graf took to Facebook to acknowledge the achievement, describing Williams as a "gift" to fans of sport.

"What an incredible performance by Serena at Wimbledon!" she wrote on Facebook.

"Such a gift to all sport fans who get to continue to watch her add to an already amazing career #22!!!

"Also, well done to Angelique making Germany so proud with her talent and fighting spirit!"

Williams is now just two short of the all-time women's record for Grand Slams, which is currently held by Margaret Court.