It was sweet revenge for the Swiss in only their second meeting since the epic Australian Open semi-final of 2005, when Safin defeated Federer 9-7 in the fifth set and went on to win the Melbourne Park crown.
A single break was sufficient for the Swiss maestro to clinch the opening set but Safin broke in game six of the second before serving for the set at 5-3.
But Federer broke back and then levelled before storming through the tie-break, winning it 7-2 to complete victory in an hour and five minutes and move into Saturday's final.
Federer, the defending Australian Open champion, opened his 2007 campaign with a three-set win over Radek Stepanek on Wednesday in his first competitive match since winning the Masters Cup in Shanghai in November.
The Australian Open starts on Monday.
