Melbourne: Federer won his record 20th Grand Slam title of his career on Sunday, overcoming Marin Cilic in five sets in the Australian Open final in Melbourne.
The Swiss legend is still second behind Rafael Nadal on top of the world rankings.
Roger Federer beat Cilic 6-2 6-7 (5-7) 6-3 3-6 6-1 to win sixth grand slam and 20th Grand Slam title.
Temperatures of 37C would not normally invoke the extreme heat policy (40C), but organisers said the humidity was behind the decision to close the roof.
“Mentally it was tough,” said losing finalist Cilic about the roof closure.
“Throughout the tournament I played all my matches outdoors, also preparing for a hot day, 38 degrees. Then first match for the final to play with the roof closed, it’s difficult.