Defending champion Lleyton Hewitt suffered a shock second round exit at Queen's Club when he lost 7-6 (7-5) 7-6 (7-2) to qualifier Jo-Wilfred Tsonga.
Hewitt was bidding for a record fifth title at Queen's
The four-times champion broke the Frenchman to take the second set to a tie-break but could not save the match.
French Open champion Rafael Nadal warmed up for Wimbledon with a 6-4 6-4 win over Juan Martin del Potro.
Alex Bogdanovic beat Jamie Baker 4-6 7-6 (7-4) 6-3 in an all-British clash, while Novak Djokovic also won.
Serbia's Djokovic, the man Nadal beat in the semi-finals in Paris, beat American Robert Kendrick 3-6 6-3 6-2.
Nadal, who received a first-round bye, barely broke sweat as he pummelled Del Potro from the back of the court.
Nadal reached the Wimbledon final last year, losing to Roger Federer, the man he beat in Paris last Sunday.
And the Spaniard said he was full of confidence ahead of this year's tournament, which starts on 25 June.
"I'm very happy with my game," said Nadal. "It's always difficult with the first game changed to a new surface.
"I got to the final last year at Wimbledon and that has given me a lot of confidence.
"I always love this surface. If I am playing well I will have chances to have results on this surface."
Fourteenth seed Arnaud Clement of France and his compatriot, 12th seed Paul-Henri Mathieu, also advanced.
Hewitt said: "I saw a bit of Tsonga's match against Andy Roddick at the Australian Open and he was a set up there and served for the second set, so I knew how flashy he was.
"He kept it up for two sets. Even in the game I broke he didn't really miss too many balls. I had to hit a couple of big returns. Even his second serve didn't let me dictate and he came up with some big shots on the lines on big points."
Tsonga, who plays Tim Henman's conqueror Marin Cilic in round three, said: "Hewitt is a very good player on grass so it's fantastic to beat him."