If too many of your ground strokes wind up slapping into the net, there's a good possibility that you're watching the ball when you shouldn't be. That probably sounds like heresy, a violation of the most basic axiom of the game...the one about always keeping your eyes on the ball.

But there is one time when you shouldn't. That's at the moment when the ball comes off your racquet. At that moment, you should be keeping your head down, concentrating on the point where the racquet met the tennis ball (notice where Roger Federer is looking in the picture above).

The temptation is natural to lift your head to see where the ball is going, and maybe even to utter a prayer to help it over the net. But lifting your head will, ironically, have just the opposite effect. It will tend to keep the ball down and send it into the net.

That's because when you lift your head too soon, it makes your lift your too soon. And that means you don't get a full swing at the ball.

Keep that head down until you've finished your stoke. Then, and only then, look up to see where your shot has gone.

Gentlemen's Singles

Rafael Nadal (2) def. Tomas Berdych (12) 6-3, 7-5, 6-4

Ladies' Singles

Serena Williams (1) def. Vera Zvonareva (21) 6-3, 6-2

Gentlemen's Doubles

Jurgen Melzer and Philipp Petzschner

def.

Robert Lindstedt (16) and Horia Tecau (16)

6-1, 7-5, 7-5

Ladies' Doubles

Vania King and Yaroslava Shvedova

def.

Elena Vesnina and Vera Zvonareva

7-6[6], 6-2

Tomas Berdych (12) def. Novak Djokovic (3) 6-3, 7-6[9], 6-3

Rafael Nadal (2) def. Andy Murray (4) 6-4, 7-6[6], 6-4

Serena Williams (1) def.  Petra Kvitova 7-6[5], 6-2

Vera Zvonareva (21) def. Tsvetana Pironkova 3-6, 6-3, 6-2

Gentlemen's Singles: Quarterfinals

Tomas Berdych (12) def. Roger Federer (1) 6-4, 3-6, 6-1, 6-4

Andy Murray (4) def. Jo-Wilfried Tsonga (10) 6-7[5], 7-6[5], 6-2, 6-2

Novak Djokovic (3) def. Yen-Hsun Lu 6-3, 6-2, 6-2

Rafael Nadal (2) def. Robin Soderling (6) 3-6, 6-3, 7-6[4], 6-1

Ladies’ Singles: Quarterfinals

Serena Williams (1) def. Na Li (9) 7-5, 6-3

Vera Zvonareva (21) def. Kim Clijsters (8) 3-6, 6-4, 6-2

Petra Kvitova def. Kaia Kanepi 4-6, 7-6[8], 8-6

Tsvetana Pironkova def. Venus Williams (2) 6-2, 6-3

Gentlemen’s Singles: 4th Round
Roger Federer (1) def. Jurgen Melzer (16) 6-3, 6-2, 6-3
Andy Murray (4) def. Sam Querrey (18) 7-5, 6-3, 6-4
Novak Djokovic (3) def. Lleyton Hewitt (15) 7-5, 6-4, 3-6, 6-4
Rafael Nadal (2) def. Paul-Henri Mathieu 6-4, 6-2, 6-2
Yen-Hsun Lu def. Andy Roddick (5) 4-6, 7-6[3], 7-6[4], 6-7[5], 9-7
Jo-Wilfried Tsonga (10) def. Julien Benneteau (32) 6-1, 6-4, 3-6, 6-1
Robin Soderling (6) def. David Ferrer (9) 6-2, 5-7, 6-2, 3-6, 7-5
Thomas Berdych (12) def. Daniel Brands 4-6, 7-6[1], 7-5, 6-3

Ladies’ Singles: 4th Round
Serena Williams (1) def. Maria Sharapova (16) 7-6[9], 6-4
Kim Clijsters (8) def. Justine Henin (17) 2-6, 6-2, 6-3
Petra Kvitova def. Caroline Wozniacki (3) 6-2, 6-0
Venus Williams (2) def Jarmila Groth 6-4, 7-6(5)
Kaia Kanepi def Klara Zakopalova 6-2, 6-4
Tsvetana Pironkova def. Marion Bartoli 6-4, 6-4
Vera Zvonareva (21) def Jelena Jankovic (4) 6-1, 3-0
Na Li (9) def Agnieszka Radwanska (7) 6-3, 6-2

Gentlemen’s Singles: 3^rd Round

Andy Murray (4) def. Gilles Simon (26) 6-1, 6-4, 6-4

Rafael Nadal (2) def. Philipp Petzschner (33) 6-4, 4-6, 6-7[5], 6-2, 6-3

Sam Querrey (18) def. Xavier Malisse 6-7[4], 6-4, 6-2, 5-7, 9-7

Robin Soderling (6) def. Thomaz Bellucci (25) 6-4, 6-2, 7-5

Jo-Wilfried Tsonga (10) def. Tobias Kamke 6-1, 6-4, 7-6[1]

Paul-Henri Mathieu def. Thiemo De Bakker 7-6[5], 7-6[6], 6-7[8], 6-4

David Ferrer (9) def. Jeremy Chardy 7-5, 6-3, 4-6, 3-6, 7-5

Julien Benneteau (32) def. Fabio Fognini 6-4, 6-1, 4-6, 6-3

Ladies’ Singles: 3^rd Round

Serena Williams (1) def. Dominika Cibulkova 6-0, 7-5

Maria Sharapova (16) def. Barbora Zahlavova Strycova 7-5, 6-3

Agnieszka Radwanska (7) def. Sara Errani (32) 6-3, 6-1

Caroline Wozniacki (3) def. Anastasia Pavlyuchenkova (29) 7-5, 6-4

Klara Zakopalova def. Flavia Pennetta (10) 6-2, 6-3

Kaia Kanepi def. Alexandra Dulgheru (31) 6-1, 6-2

Na Li (9) def. Anastasia Rodionova 6-1, 6-3

Petra Kvitova def. Victoria Azarenka (14) 7-5, 6-0

Gentlemen’s Singles: 3^rd Round

Roger Federer (1) def. Arnaud Clement 6-2, 6-4, 6-2

Lleyton Hewitt (15) def. Gael Monfils (21) 6-3, 7-6[9], 6-4

Novak Djokovic (3) def. Albert Montanes (28) 6-1, 6-4, 6-4

Andy Roddick (5) def. Philipp Kohlschreiber (29) 7-5, 6-7[5], 6-3, 6-3

Jurgen Melzer (16) def. Feliciano Lopez (22) 4-6, 6-3, 6-2, 6-4

Thiemo De Bakker def. John Isner (23) 6-0, 6-3, 6-2

Yen-Hsun Lu def. Florian Mayer 6-4, 6-4, 2-1 (Retired)

Tomas Berdych (12) def. Denis Istomin 6-7[1], 7-6[5], 6-7[8], 6-3, 6-4

Paul-Henri Mathieu def. Mikhail Youzhny (13) 6-4, 2-6, 2-6, 6-3, 6-4

Daniel Brands def. Victor Hanescu (31) 6-7[7], 6-7[3], 7-6[7], 6-3, 3-0 (Retired)

Ladies’ Singles: 3rd Round

Justine Henin (17) def. Nadia Petrova (12) 6-1, 6-4

Venus Williams (2) def. Alisa Kleybanova (26) 6-4, 6-2

Kim Clijsters (8) def. Maria Kirilenko (27) 6-3, 6-3

Jelena Jankovic (4) def. Alona Bondarenko (28) 6-0, 6-3

Tsvetana Pironkova def. Regina Kulikova 6-4, 6-0

Vera Zvonareva (21) def. Yanina Wickmayer (15) 6-4, 6-2

Marion Bartoli (11) Greta Arn 6-3, 6-4

Jarmila Groth def. Angelique Kerber 6-3, 7-5

Gentlemen’s Singles: 2^nd Round

Andy Murray (4) def. Jarkko Nieminen 6-3, 6-4, 6-2

Rafael Nadal (2) def. Robin Haase 5-7, 6-2, 3-6, 6-0, 6-3

Sam Querrey (18) def. Ivan Dodig 6-2, 5-7, 6-3, 7-6[10]

Robin Soderling (6) def. Marcel Granollers 7-5, 6-1, 6-4

Jo-Wilfried Tsonga (10) def. Alexandr Dolgopolov 6-4, 6-4, 6-7[5], 5-7, 10-8

David Ferrer (9) def. Florent Serra 6-4, 7-5, 6-7[6], 6-3

Thomaz Bellucci (25) def. Martin Fischer 6-7[11], 7-6[4], 7-6[1], 6-2

Philipp Petzschner (33) def. Lukasz Kubot 6-4, 3-6, 4-6, 6-3, 6-2

Xavier Malisse def. Julian Reister 6-7[7], 6-4, 6-1, 6-4

Gilles Simon (26) def. Illya Marchenko (Walkover)

Julien Benneteau (32) def. Andreas Beck 3-6, 6-2, 4-6, 7-6[5], 6-3

Tobias Kamke def. Andreas Seppi 3-6, 6-2, 6-3, 6-4

Fabio Fognini def. Michael Russell 3-6, 5-7, 7-5, 7-6[6], 6-3

John Isner (23) def. Nicolas Mahut 6-4, 3-6, 6-7[7], 7-6[3], 70-68

Jeremy Chardy def. Lukas Lacko 6-3, 7-6[4], 4-6, 6-7[5], 8-6

Ladies’ Singles: 2^nd Round

Caroline Wozniacki (3) def. Kai-Chen Chang 6-4, 6-3

Maria Sharapova (16) def. Ioana Raluca Olaru 6-1, 6-4

Serena Williams (1) def. Anna Chakvetadze 6-0, 6-1

Barbora Zahlavova Strycova def. Daniela Hantuchova (24) 1-6, 6-2, 6-4

Alexandra Dulgheru (31) def. Romina Sarina Oprandi 6-2, 6-0

Kaia Kanepi def. Edian Gallovits 6-4, 7-5

Anastasia Rodionova def. Svetlana Kuznetsova (19) 6-4, 2-6, 6-4

Victoria Azarenka (14) def. Bojana Jovanovski 6-1, 6-4

Domninka Cibulkova def. Ayumi Morita 6-7[4], 7-6[2], 7-5

Anastasia Pavlyuchenkova (29) def. Roberta Vinci 6-2, 7-6[1]

Na Li (9) def. Kurumi Nara 6-2, 6-4

Klara Zakopalova def. Aravane Rezai (18) 5-7, 6-3, 6-3

Petra Kvitova def. Jie Zheng (23) 6-4, 2-6, 6-2

Agnieszka Radwanska (7) def. Alberta Brianti 6-2, 6-0

Flavia Pennetta (10) Monica Niculescu 6-1, 6-1

Sara Errani (32) def. Arantxa Parra Santoja 6-2, 6-2