UPDATE 4-Tennis-Federer tames Karlovic at Rome Masters

(adds Davydenko defeat)

By Paul Virgo

ROME, May 8 (Reuters) - World number one Roger Federer beat Croatia's Ivo Karlovic 7-6 6-3 in the Rome Masters on Thursday to book a quarter-final against Czech Radek Stepanek.

Earlier, Australian Open champion Novak Djokovic edged past Russia's Igor Andreev 6-3 3-6 6-3 in his third round match and will face Spain's Nicolas Almagro in the last eight.

Russian fourth seed Nikolay Davydenko fell by the wayside after he was edged out 4-6 6-2 7-6 by Spain's Tommy Robredo.

Top seed Federer's fluid tennis met stubborn resistance from Karlovic in the first set. The Croat, aided by some brutal serves, saved four break points in the eighth game and a set point in the 12th before losing the tiebreak.

Federer then drilled a forehand on to the line to clinch the third of three break points in the fifth game of the second and broke again in the final game to cruise home.

The Swiss player admitted that the towering Croat's big serves were hard to handle initially.

"It's completely different to any other serve out there because of his size and he backs it up well at the net," he told a news conference. "He puts a lot of pressure on you because he can hit all four corners very easily.