Rafael Nadal extended his Grand Slam winning streak to 23 matches, continuing the chase for his “Rafa Slam” with a 6-2, 6-1, 6-1 win over American qualifier Ryan Sweeting in the second round of the Australian Open.Rafael Nadal keeps his eyes on the ball as he makes a backhand return to Ryan Sweeting during their second round match at the Australian Open in Melbourne on Thursday. APThe top-ranked Nadal is aiming to be the first man since Rod Laver in 1969 to hold all four Grand Slam titles at the same time.He’s conceded only four games en route to the third round, sealing his win over Sweeting on Thursday with the last in a blizzard of forehand winners.After his quarterfinal exit at the last Australian Open, Nadal rebounded to win the French, Wimbledon and U.S. Open titles.Nadal hit some shots that Sweeting could barely believe, including a forehand on set point in the second when the Spaniard’s curling shot caught the baseline. With nothing to lose, Sweeting challenged the call as he walked off. The call stood.The only hint of anything other than complete domination for Nadal came in the third set, when Sweeting broke serve in the fifth game and then got within a point of bring it back to 4-2 in a game that went to deuce five times. Again, Nadal held on to convert a break and served out in the next game.”A few mistakes with the backhand, that’s all. My serve improved a lot since the first day. I think I was serving very well today,” Nadal said, noting the one blot on his serve was when he looked into the sun. “Movement good; backhand good; having a few more mistakes than usual. I have to play longer with the backhand. Maybe have to play a little bit more aggressive, more inside the court.”advertisementThat’s not good news for Nadal’s next opponent – 18-year-old Australian wildcard entry Bernard Tomic.Sweeting said he was overwhelmed by Nadal’s relentless accuracy and the fact he had to play so many shots just to earn a point.Tomic, the last Australian male left in the draw, advanced with a 7-6 (4), 7-6 (3), 6-3 win over No. 31 Feliciano Lopez of Spain. Canada’s Milos Raonic also produced a second-round upset, beating No. 22 Michael Llodra of France 7-6 (3), 6-3, 7-6 (4).Kim Clijsters showed why she’s fast becoming a hot favorite for the women’s title by beating Carla Suarez Navarro 6-1, 6-3.U.S. Open champion Clijsters opened with a 6-0, 6-0 win over former No. 1-ranked Dinara Safina, but Suarez Navarro was a potentially dangerous second-round matchup. The 22-year-old Spaniard beat Venus Williams in a second-round upset in her first trip to Melbourne Park two years ago.”She is a tough player. She’s tricky. The balls bounce so much different than for my first round,” Clijsters said. “I was just happy with the way that I played. I tried to play both sides of the court, tried to be aggressive and dictate the points. And it worked.”With defending champion Serena Williams not playing in Australia due to a prolonged foot problem, third-seeded Clijsters is hopeful of going one better than her previous best performance at Melbourne Park – she lost the 2004 final.Her third-round 6-0, 6-1 loss here to Nadia Petrova last year was her worst in a major. It’s a defeat she claims she doesn’t dwell on and doesn’t think will influence her preparations for the same stage this weekend.”I don’t think I’ve ever played a match like that. So it was very easy in a way to also forget about it, as well,” Clijsters said.Joining her in the third round from the bottom half of the draw were No. 10 Shahar Peer, No. 12 Agnieszka Radwanska, No. 13 Nadia Petrova and Iveta Benesova, who beat No. 18 Maria Kirilenko 6-3, 6-1.Seventh-seeded Jelena Jankovic lost 7-6 (3), 6-3 to China’s Peng Shuai, continuing an unimpressive streak of seven losses in eight matches. It was former world No. 1 Jankovic’s worst result at a major since the 2009 U.S. Open.Meanwhile, Clijsters has spent just two hours on court so far, leaving plenty of time to joke with the crowd and take a little swipe at on-court interviewer Todd Woodbridge, a former Australian doubles great. She lightheartedly chided Woodbridge about a text message he’d sent to fellow Australian Rennae Stubbs, suggesting Clijsters was showing physical and emotional signs of being pregnant.”No, I’m not!” said Clijsters, who took time off the tour when she married and had a child – daughter Jada, born in February 2008 – before returning to win the U.S. Open in 2009.advertisementWhile Clijsters and Nadal have advanced with ease, Venus Williams and defending men’s champion Roger Federer have encountered challenges.Williams injured a muscle between her stomach and groin Wednesday as she twisted for a volley. She needed a medical timeout after losing the first set. She was on the verge of tears, and apparently elimination. But she refused to stop playing and eventually beat Sandra Zahlavova of the Czech Republic 6-7 (6), 6-0, 6-4.Federer faced a more familiar problem – Gilles Simon. He’s one of only three men on tour with a winning record against the Swiss great.The 16-time Grand Slam champion admitted he was “happy I survived a scare” after winning in five sets.