Novak Djokovic offered his best impersonation of new coach Boris Becker on and off the court in another flawless performance as he reached the quarter-finals of the Australian Open yesterday. The three-time defending champion crushed Italy's 15th seed Fabio Fognini 6-3, 6-0, 6-2 to book his place in the last eight without losing a set. The Serb dropped just 10 points on his serve - Becker's speciality - in the entire match and Fognini was left to resort to joking around in the third set in an attempt to distract his second-seeded opponent. I'm going to gain a few kilos and have to colour my hair in order to do the proper Becker imitation Novak Djokovic But the real fun came afterwards when the Serb impersonated the service action, walk and mannerisms of Becker, as the German looked on from the stands. "I saw his facial reactions," Djokovic said. "The first impression, when I did all the serves, he was happy and was applauding. "When I said how he is today with his problems in the back and everything, he was not so happy about that. He was upset. But, no, it's all for good laughs. "It's actually the first time after a long time that I've actually done a Becker imitation. I don't know how I was. "Was it OK? I'm going to gain a few kilos and have to colour my hair in order to do the proper Becker imitation," Djokovic joked. If Djokovic saved the fun stuff for after the match, he was deadly serious during it as he ripped apart Fognini with ruthlessly efficient hitting. After breaking once to win the first set, Djokovic rattled off 14 of the next 15 points on his way to a 4-0 lead in the second. Fognini enjoyed the best year of his career in 2013, but was powerless against Djokovic, who admits he is happy with all parts of his game. "I feel great about myself in this moment," the Serb said. "There is this confidence that I carry on, obviously, from many wins that I had in the last two months of the 2013 season and I started off this season in a good style. I'm trying to keep it up." Djokovic, who next plays either eighth seed Stanislas Wawrinka or number 17 Tommy Robredo, said the hardest challenge had been keeping a straight face while Fognini did his comedy act, at one stage throwing his racquet over the net towards the second seed. "It was funny," he said. "But you cannot get carried away too much. You can lose focus so easily on the court, really. Anything can distract you. "Tennis is such a mental game at the end of the day. It's very dynamic. Everything happens fast. In one or two points, you can lose break and the match can turn around. "That's why it's important to really stay within yourself and, you know, focus on what you can do," he said. Tomas Berdych trounced Kevin Anderson 6-2, 6-2, 6-3 in a battle of big servers to set up a quarter-final with Spanish hustler David Ferrer. Berdych, wearing his trademark blue-and-white striped shirt, outgunned Anderson at a rowdy Margaret Court Arena with an impressive array of winners to extend his win-loss record to 10-0 over the South African beanpole. Ferrer reached the quarter-finals for a fourth successive year by overhauling unseeded German Florian Mayer 6-7 (5-7), 7-5, 6-2, 6-1.