Tennis legend Serena Williams has said she's 'so proud' of Kim Clijsters after her comeback defeat at the Dubai Duty Free Tennis Championships.

Clijsters played for the first time in more than seven years yesterday after retiring for a second time in 2012.

And despite losing in straight sets to Australian Open finalist Garbiñe Muguruza, the Belgian put up a valiant fight in her return match.

Following the conclusion of the match, Williams said she is inspired by Clijsters comeback.

She said: “Seriously so so so proud of Kim Clijsters. You inspire me. Wow. Just wow congrats you did amazing.”