Shock defeats of top seeds yesterday boosted the dream of having a British winner at Wimbledon in the Queen's Golden Jubilee year.

Three of the game's biggest names were sent crashing out of the tournament as the third day drew to a close.

Americans Andre Agassi and Pete Sampras and Russian Marat Safin were sent packing by relative unknowns.

Add to that the demise of 14th seed Thomas Enqvist at the hands of Mark Philippoussis and 12th seed Jiri Novak to Wayne Arthurs and you had a grim day for the top 20.

The results will give a huge boost to Britain's hopes for glory after Greg Rusedski battled through to the third round. Tim Henman was also expected to progress when he played today.

Seven times champion Sampras made his most emotional exit from Wimbledon after crashing out to outsider George Bastl, from Switzerland, in a five set thriller, losing 3-6, 2-6, 6-4, 6-3, 4-6.

Agassi, who was seeded 3 for the tournament, lost to Thailand's Paradorn Srichaphan 4-6, 6-7, 2-6.

Russia's Safin, the second seed, lost to Belgium's Olivier Rochus 2-6, 4-6, 6-3, 6-7.

Sampras vowed "I'll be back", after falling victim to the biggest shock in the history of upsets at Wimbledon's graveyard of champions.

"This is not the way I'm going to end it here," pledged a disconsolate Sampras, upset at being forced to play on Court Two after winning Wimbledon a record seven times.

The notorious, tightly-packed court has seen some huge upsets over the years but none come bigger than lucky loser Bastl's triumph over a champion regarded by many judges as the best ever to play the game.

Bastl, a Swiss tennis journeyman ranked 145 in the world, lost in the qualifiers last week and only got into Wimbledon when Spain's Felix Mantilla withdrew through injury.

But he refused to be overawed by the reputation of Sampras who dug a huge hole for himself, climbed out and promptly fell back in.

"It all happened so quickly from four-all, a matter of five minutes, boom, I lost the match. It's not a feeling that I like, especially here at Wimbledon," said Sampras.

The calls for him to quit have inevitably resurfaced but, whatever Sampras has lost from his game, he still has the pride of a great champion and when he goes he wants to leave in the style of an all-time great from an arena befitting the one of the giants of tennis history.

"I'm not going to give in to the critics. I'm going to stop on my own terms, not when someone else thinks I should," said Sampras, who revealed the thoughts which went through his mind as he sat disconsolately, head bowed, while Bastl enjoyed his victory salute before trudging off without a backward glance.

Agassi admitted he was stunned by the defeat, saying he had been unable to find any rhythm against an opponent on top form.

"I am in shock," he said.

"I don't look at it as a reflection of the state of my game at the moment. Paradorn did really well but I should be doing better than that."

Agassi said a vital line call at the end of the second set could have made a difference if it had gone his way but he might have still found it difficult to win.

"It was a big point," he said. "There is a huge swing between being level and going two sets down.

"I thought the ball was long but you see calls like that all the time."

Rochus's plan to make Safin "get crazy" paid off in style.

The tiny Belgian revealed how his pre-match tactics were to wind up the Russian who, at 6ft 4in, held an 11 inch height advantage.

He said: "I knew Marat sometimes gets nervous so I knew I had to play every point and that maybe some games he will give me because he will get crazy.

"I just stayed focused, tried to play every ball the same and fight."