MELBOURNE (REUTERS) - A patient Roger Federer weathered a second set storm from Grigor Dimitrov before slapping down the Bulgarian challenger 6-4, 3-6, 6-1, 6-4 to reach the fourth round of the Australian Open and clinch his 300th win in Grand Slams.

Long in the shadow of the Swiss master, Dimitrov played some irresistible tennis to prise a set but was powerless to maintain the intensity under a closed roof at Rod Laver Arena.

Federer, however, simply lifted a gear, taming an occasionally wayward forehand before speeding away from the Bulgarian player nicknamed "Baby Fed".

Capturing an early break in the final set, four-time champion Federer sealed the match with an imperious forehand to set up a clash with another young gun in Belgian David Goffin.