NEW YORK (AFP) Top seed Caroline Wozniacki and former world number one Maria Sharapova booked a fourth-round showdown with straight-set US Open triumphs on Saturday while Roger Federer cruised into the last 16 as well. Danish 20-year-old Wozniacki, last years US Open runner-up, routed Taiwans Chan Yung-Jan 6-1, 6-0, while Russian 14th seed Sharapova, whose three Grand Slam titles include the 2006 US Open, blanked American Beatrice Capra 6-0, 6-0. Wozniacki has lost only three games in three matches, the best US Open run since Chris Evert dropped only two in the same span in 1976. No woman at any Slam has lost so few games so late since Mary Pierce at the 1994 French Open. She can run all day and get a lot of balls back and make you hit tons of balls, Sharapova said. She changes pace really well and gets her opponents off balance. She does many things well. Thats why shes at the top. It will be tough and I am looking forward to it. Sharapova, whose blanking of Capra was the latest US Open womens shutout since Martina Navratilova won by the same score in 1989, beat Wozniacki twice in 2008 in their only prior meetings. But since then, Wozniacki has risen through the ranks to become world number two behind Serena Williams, going 17-1 with three titles since Wimbledon. She is a good player, a tough match up, Wozniacki said. We will see what happens on Monday. A showdown is brewing on the mens side as well as Federer, a 16-time Grand Slam champion seeking his sixth US Open title and seventh consecutive trip to the final, and Swedish fifth seed Robin Soderling reached the fourth round. World number two Federer smashed 13 aces and 31 winners to beat 109th-ranked Frenchman Paul-Henri Mathieu 6-4, 6-3, 6-3 while Soderling defeated 48th-ranked Dutchman Thiemo de Bakker 6-2, 6-3, 6-3. Both triumphs came in brisk winds. Tough conditions to play in, especially if youre down in the score, said Federer. You could tell Mathieu was really struggling after being down. His serve, his returns, everything kind of falls into pieces. French Open runner-up Soderling broke Federers streak of 23 Grand Slam semi-finals in a row with a quarter-final triumph on the Paris red clay over the Swiss superstar who had won their 12 prior matches. Soderling, who lost the Roland Garros final to top-ranked Rafael Nadal, and world number two Federer each need one more victory to book a rematch on the Flushing Meadows hardcourts. Everybody has been telling me since the draw came out Im playing Roger in the quarters. Its still far ahead, Soderling said. Its always difficult to play against Roger and I have played him a lot of times. In any tournament they play, Roger and Rafa will be the favorites, but there are a lot of players who can beat them. Federer next faces Austrian 13th seed Jurgen Melzer, whom Federer ousted in this years fourth round at Wimbledon in their only prior meeting. Soderling will meet Spanish 21st seed Albert Montanes, who led 6-2, 2-1 when 147th-ranked Japanese qualifier Kei Nishikori retired after only 38 minutes with a groin injury. Also advancing to the fourth round was Serbian third seed Djokovic, who downed US wildcard James Blake 6-1, 7-6 (7/4), 6-3 to book a date with US 19th seed Mardy Fish. The days biggest upset came on the womens side when Serbian fourth seed Jelena Jankovic, a former world number one who was a 2008 US Open runner-up, was wind-hampered and lost 6-2, 7-6 (7/1) to Estonian 31st seed Kaia Kanepi. It was really difficult, Jankovic said. I didnt have a chance to play good tennis in these conditions. Kanepi will next play Belgian Yanina Wickmayer, a 2009 US Open semi-finalist who saved a match point in the final tie-breaker before beating Swiss veteran Patty Schnyder 7-6 (7/5), 3-6, 7-6 (8/6). Meanwhile, Roger Federer says that Rafael Nadal has a solid chance to become the greatest player in tennis history, but to do so will require the Spaniard win a US Open title to complete a career Grand Slam. World number two Federer, a record 16-time Grand Slam winner seeking his fifth US Open title, advanced to the fourth round on Saturday by defeating Frances 109th-ranked Paul-Henri Mathieu 6-4, 6-3, 6-3. After the match, Federer said world number one Nadal is young enough at 24 and talented enough to claim the best-ever tag, but it would require the five-time French Open winner and eight-time Grand Slam champion to win the only Slam title that has eluded him on the New York hardcourts. Yeah, clearly has a chance because hes young enough, Federer said. So many French Open titles to his name just alone at his age is an amazing accomplishment. Plus hes had some incredible clay court records that are going to be very hard to beat. Then again, obviously I guess he would need to win the US Open, put himself there. He has won the Olympics, done some amazing things. So hell have a shot at it, Im sure. Nadal has lost in the US Open semi-finals the past two years, what could be seen as the start of a run similar to Federers at the French Open, where he made a 2005 semi-final and the next three finals before a breakthrough title. I guess its somewhat similar, Federer said. I won the other three Grand Slams rather quickly, like he did as well. The only difference so far is that I lost two finals plus a semis before, whereas hes never been in a finals here. Nadal, who would be the seventh man to complete a career Slam with a title at the end of the Flushing Meadows fortnight, said early Saturday the US Open crown is not his obsession even as he called Federer as the games greatest. Maybe for Roger it was a big goal because he is the best of history and he needed Roland Garros, Nadal said. He deserved Roland Garros because he did three finals, another semi-finals. Another amazing Federer feat, the between-the-legs while running from the net shot, was duplicated Friday at the US Open by Italys Francesca Schiavone, although Federer joked it might be easier for a woman to pull it off. Well, yeah, because they never come to the net so theyll never be lobbed, Federer said. No, Ive seen her hit some very good shots in the past. She has a great ability to come up with some different kind of variation for a womans player, which is nice to see. She played incredible at the French Open. Shes not scared of trying out a few things. Thats why I kind of like to watch her. Djokovic reaches fourth round at US Open Serbian third seed Novak Djokovic advanced to the fourth round of the US Open on Saturday by defeating 108th-ranked US wild card James Blake 6-1, 7-6 (7/4), 6-3. Djokovic, who lost the 2007 US Open final and US Open semi-finals the past two years to Roger Federer, will play American 19th seed Mardy Fish for a berth in the quarter-finals.