Djokovic played against two match points at 3-5, denying them with winners and extending the battle with a service winner. Federer served for the win in game ten and sealed the deal with a backhand volley winner, booking the title clash against Gilles Simon.

Former world No.1 and U.S. Open champion Dominic Thiem will retire at the Vienna Open later this month and tennis' biggest names have sent heartfelt messages.

Roger Federer, Rafael Nadal and Novak Djokovic are all in contention for being dubbed the greatest tennis player to walk the Earth, and one coach who has played with all three has had his say

The former world No. 3 is ready to say goodbye at his home tournament, the Vienna Open, at the age of 31. Thiem has already extended a retirement party invitation to Roger Federer, Rafael Nadal and Novak Djokovic after they sent him heartfelt messages ahead of his farewell.