Roger Federer cruising but tougher tests await

• Roger Federer enjoyed a comfortable fourth-round victory over Austria's Jurgen Melzer Picture: Getty

The 16-times Grand Slam champion is through to the quarter-finals and in majestic form, but most of his main rivals are, too. Only Andy Murray has made an early exit.

Federer booked his place in the last eight with a 6-3, 7-6, 6-3 win over Jurgen Melzer at the Arthur Ashe Stadium without ever having to play at his best.

It will take a mighty performance from his rivals to stop him capturing a sixth title at Flushing Meadows, but there are some willing challengers ahead.

His next opponent is Robin Soderling, the big-hitting Swede who ended Federer's French Open defence earlier in the season. If he gets through that, Federer could then face Serbia's Novak Djokovic, who beat him in the semi-finals at the Australian Open in 2008.

There is also Rafa Nadal, as always, lurking on the other side of the draw if they both reach the final. Federer may be the greatest player of all time, but nothing is ever assured.

Soderling and Djokovic also moved through to the quarter-finals by winning on Monday. Soderling overcame Albert Montanes, one of six Spaniards who made the last 16 of the men's draw, 4-6, 6-3 6-2, 6-3. It was a workmanlike performance, but Djokovic was all class and looks the more threatening. The world No 3 demolished the improving American Mardy Fish 6-3, 6-4, 6-1 and is steadily building momentum and confidence.

Federer is yet to drop a set in the tournament and hardly got out of second gear against Melzer. He did have some problems with his serve and was broken once each in the first and third sets, but was able to raise his game when it mattered. Boris Becker, watching from the stands, nodded in approval.

After the match, Federer shook hands with Alex Rodriguez and was invited to watch his New York Yankees play. "I've never been to a baseball game so that's something on the 'to do' list for me," Federer said.

Next in line for Djokovic is Gael Monfils who overpowered his countryman Richard Gasquet 6-4, 7-5, 7-5 to become the first Frenchman in a decade to reach the US Open quarter- finals.

"It's very encouraging at this stage of the tournament that I'm raising my game and feeling more comfortable on the court," Djokovic said. "I played a great match today." Soderling has developed a reputation of a giant-killer after beating Nadal at the French Open last year and Federer this season.

The odds are stacked against toppling Federer on the super-fast courts in New York, but he holds no fears.

"I've played Roger many times. I know his game and he knows mine," Soderling said.

Against Montanes, Soderling only faced one break point - which Montanes converted to win the first set.

Soderling dominated the next three sets, breaking Montanes five times. He also served 15 aces.

Last night, Russia's Mikhail Youzhny showed typical grit to move into the quarter-finals, beating Tommy Robredo of Spain 7-5, 6-2, 4-6, 6-4.