Chair umpire Damian Steiner told her to put it away. Scolded her like a schoolgirl.

"He told me I couldn't use my notes," Williams said after a 6-4, 7-6 (4) win that put her into the fourth round. "I was like, 'Well, it's not like I'm Harry Potter and my dad can magically give me notes to read.'

"It's something that I write myself. Just little things. What if I were to take a paper on the court and write something, what's the difference?" she said.

A moment later, Steiner relented.

"Players can read whatever they want to read on the changeover - as long as they haven't received anything from anywhere else," tournament referee Brian Earley said. "A ball kid hands them a note - that would be construed as coaching. But there's nothing to prevent a player from opening a book that she brought with her."

Earlier in this tournament, in fact, wild-card entry Ahsha Rolle read notes that she kept in a Bible. Pete Sampras used to peruse notes from his wife. And Jim Courier once kept a copy of Armistead Maupin's "Maybe the Moon" at courtside, saying it was too hard to put away.

The Write Stuff, indeed.

Venus Williams coasted past No. 21 Alona Bondarenko 6-1, 6-2 and kept on track for a semifinal meeting with her sister.

"She's obviously an unbelievable competitor. When push comes to shove, she shoves," Venus said. "I'm not too worried about whether or not she's going to make it."

There was concern about No. 2 Rafael Nadal's knees. They hurt so badly last week that he thought about pulling out of the tournament, but an abbreviated 6-2, 6-3, 3-2 win over Janko Tipsarevic - who quit because an injured rib muscle - certainly helped.

"I feel so much better today," Nadal said.

On a day when several more players needed medical treatments, rubdowns or ice during matches, No. 3 Novak Djokovic and No. 8 Tommy Robredo also advanced into the third round on the men's side.

But former Open champions Lleyton Hewitt and Marat Safin lost and so did Tim Henman, ending his Grand Slam career.

Henman turns 33 next week and previously announced he would be retiring. The end came in the second round with a 7-6 (2), 2-6, 7-5, 6-4 loss to Jo-Wilfried Tsonga of France.

"I feel clear in my mind. Tennis has served me well," Henman said. "Time is time."

In the women's draw, No. 1 Justine Henin, No. 3 Jelena Jankovic, No. 5 Ana Ivanovic and No. 10 Marion Bartoli moved into the fourth round.

With record crowds flocking to Flushing Meadows, the most eagerly awaited match was set for Saturday. That's when three-time Open champ Roger Federer was to take on 6-foot-9 rookie John Isner.

Djokovic won Friday's most entertaining match, outlasting sometime-doubles partner Radek Stepanek 6-7 (4), 7-6 (5), 5-7, 7-5, 7-6 (2).

They ran all over the court, hitting shots from crazy angles for nearly five hours. They wound up playing 63 games, the most at the U.S. Open since 1979 when John Lloyd and Paul McNamee also did it.

By the time Djokovic and his pal were done, they'd played 356 points.

"I am totally exhausted. No energy," Djokovic said. "I smell my shoes - they are so stinky."