Roger Federer, Serena Williams and Andy Murray are the headline acts at the U.S. Open on Monday as two bitter rivals resume hostilities after they refused to shake hands at the first major championship of the year.

Top-seeded Federer will play 23rd-seeded American Mardy Fish during the day session in Arthur Ashe Stadium before Murray, the Olympic champion, takes on big-hitting Canadian Milos Raonic during the prime-time night session.

Federer's match will be preceded by Williams against Czechoslovakia's Andrea Hlavackova for a place in the quarter-finals.

The first match on Louis Armstrong Stadium has an edge with sixth-seeded Czech Tomas Berdych meets 11th-seeded Spaniard Nicolas Almagro.

The pair played a heated match in the fourth round of the Australian Open when they refused to shake hands after Berdych completed his four-set triumph.

Berdych claimed Almagro had deliberately tried to strike him with a forehand during the match and left the court in Melbourne while Almagro waited at the net to shake hands.

Afterwards, both players claimed the other was in the wrong. They have played twice since, at Indian Wells (California) and Rome, recording one win apiece.

Murray and Raonic looms as the match of the day.

"Milos has a huge serve," Murray said. "He's improved a lot from the back of the court. He goes for his second serve. This is his best year on tour so far and it will be tough."

Raonic has hit a tournament-leading 89 aces compared to just 33 from Murray.

"He has the potential to win majors," Murray said. "When you have big, big weapons, that obviously helps. He's obviously playing better and better.

"He's had some good wins this year but he's also had some tough losses. He lost close ones at theOlympics and Wimbledon but he's gaining experience all the time."

The third-seeded Murray is trying to break through for the first major championship of his career.