MELBOURNE - Rafael Nadal put on an awesome performance to reach the Australian Open last 16 on Saturday and Roger Federer and Andy Murray also hit top gear as the title race began to narrow. With Victoria Azarenka a class apart in her third-round win, Nadal stormed past France's Gael Monfils 6-1, 6-2, 6-3 to underline his challenge to Novak Djokovic's three-year Melbourne reign.Federer was typically fluent in his 6-2, 6-2, 6-3 win against Teymuraz Gabashvili and Murray, continuing his strong recovery from back surgery, was a convincing winner over Feliciano Lopez. With sharply cooling temperatures bringing an abrupt end to four days of 40 Celsius (104 Fahrenheit), there was a businesslike feel as the men's and women's contenders set about reaching week two.Federer said his Grand Slam struggles last year, when he fell early at Wimbledon and the US Open, were past him as he dismantled Russia's Gabashvili, the world number 79. "It was a tough year last year and it took some time to figure out what I needed to do to feel better and to get my confidence back, because that's what I thought it was mostly," said Federer, seeded six."For the last four to five months I feel that I'm back to normal again and at least I feel I've done the work to catch up and haven't had any setbacks, so it's very positive." Murray gave a brief scare when he clutched his back in the first set but he moved unhindered thereafter to win 7-6 (7/2), 6-4, 6-2 and move into the round of 16 without dropping a set. "Today was a big step up for me. Feliciano is a top-30 player. He's a tricky opponent to play," Murray said.In the evening session, Nadal was superior in all departments to the entertaining but inconsistent Monfils, winning in just over two hours. Nadal will next face Japanese number one Kei Nishikori, who reeled off the last 10 games against Donald Young to end American interest in the men's competition. Bulgaria's Grigor Dimitrov weathered Milos Raonic's powerful serve to reach his first Grand Slam last 16, where he will face Roberto Bautista Agut, the Spanish surprise package who ousted Benoit Paire.France's Stephane Robert became the first "lucky loser" to reach the Australian Open fourth round when he beat Slovakia's Martin Klizan. His prize is a match with Wimbledon champion Murray. And in an all-French clash, 2008 finalist Jo-Wilfried Tsonga ended the injury-defying run of Gilles Simon, who hobbled out of last week's Kooyong Classic, to go into a clash with Federer. Meanwhile in the women's draw, Azarenka destroyed hapless Austrian Yvonne Meusburger for the loss of just one game, winning 6-1, 6-0 to set up a rematch of last year's semi-final with Sloane Stephens.Stephens beat Elina Svitolina to progress and she said last year's controversy, when Azarenka was accused of using a medical timeout to calm her nerves at a critical moment, would have no bearing. "That has nothing to do with this year. I don't even remember half the stuff that happened. It's okay," said the 20-year-old American. Former champion Maria Sharapova, returning from a shoulder injury, faced down a challenge for a second successive match before beating France's Alize Cornet 6-1, 7-6 (8/6).Sharapova will next play Slovakian seed Dominika Cibulkova, who beat Spain's Carla Suarez Navarro. Serbia's Jelena Jankovic won against Kurumi Nara to set up a meeting with Romanian Simona Halep. But former world number one Caroline Wozniacki took a tumble when she was shocked by the unheralded Garbine Muzuruga, 20, who extended her best ever Grand Slam run. Next up for the emerging Spanish star is Polish fifth seed Agnieszka Radwanska, who came from a set down to oust Russia's Anastasia Pavlyuchenkova.