Roger Federer took less than an hour to beat Tobias Kamke 6-2 6-1 and book his place in the Brisbane International quarter-finals.

The Swiss top seed comes into the tournament as defending champion, having beaten Milos Raonic in last year's final.

Federer had to beat Grigor Dimitrov in the last four on that occasion and it is the Bulgarian who awaits the world number three in the next round.

Two breaks in the opening set teed Federer up for the victory over qualifier Kamke and he won six games on the bounce in the second to seal his progression and stop the clock on 55 minutes.

Dimitrov was on court more than three times longer than Federer as he battled to a 5-7 7-6 (8-6) 6-2 win against Viktor Troicki.

After being edged out in the first set, Dimitrov led 5-1 in the second-set tie-break, but needed three set points before he finally made it count.

The world number 28 eventually put the contest to bed when converting his fourth match point in the decider.

Fourth seed Raonic made a winning start to his campaign by beating Ivan Dodig 6-7 (2-7) 6-1 6-4, while Lucas Pouille pulled off an upset to send David Goffin packing in a 7-6 (7-5) 4-6 6-3 win.