Canada's Milos Raonic prepares to serve during his first round tennis match against Japan's Tasuma Ito at the 2012 Summer Olympics Monday at the All England Club in Wimbledon.Ryan Remiorz/The Canadian Press
On back courts at Wimbledon that housed just three rows of seats -- packed almost entirely with red and white-clad fans -- Canada's tennis Olympians rolled through Monday's competition.
Daniel Nestor and Vasek Prospisil sliced their way to a dramatic 6-3, 7-6 (11-9) win over the Romanian team of Adrian Ungur and Horia Tecau. Nestor and Prospisil will next face Serbia's Nenad Zimonjic and Janko Tipsaravec.
Their victory was just hours after Milos Raonic and Alexandra Wozniak each finished off their first opponents in singles at the London Games.
Raonic, the world No. 25, struggled with unforced errors on the day, but overcame a push from Tatsuma Ito of Japan at the London Games to triumph 6-3, 6-4. It sets up a Tuesday matchup with world No.6 Jo-Wilfred Tsonga of France.
The native of Thornhill, Ont. put the Japanese No. 68 on his heels with his signature thundering serve. He delivered 10 aces on the day, drilling the court's scoreboard with the ball several times, often sending it skipping off Ito's racket clear into the crowd.
Raonic said the win wasn't as pretty as he would have liked. He had 19 unforced errors on the day.
"A few things were a little disappointing, but in general, the goal was to win," said Raonic. "I wish I could have stayed on top of myself a little more."
Raonic wasn't fazed by the mistakes and chalked it up to a lack of game experience on grass.
"I don't think I have more than 10 matches on grass in my career," said Raonic. "It's understanding that things aren't going to be pretty, but the main goal is to win. The more matches I can win, doesn't matter how poorly I play, the more opportunities I give myself to pick up experience and knowledge on the surface."
A few courts over at the All England Club, Wozniak took down New Zealand's Marina Erakovic 6-2, 6-1. Her next opponent will be Venus Williams.
Williams began her bid for a record fourth gold medal by beating Sara Errani of Italy, 6-3, 6-1.
It was an impressive showing from Williams, who is unseeded and drew a tough first-round foe. Errani has won four titles this year, was the runner-up at the French Open and is ranked a career-high No. 9.
But Williams was in fine form on the Wimbledon grass, where she has won five of her seven Grand Slam titles.
Twenty minutes after Williams won on Court 2, younger sister Serena closed out a second-round victory on Court 1, beating Urszula Radwanska of Poland, 6-2, 6-3. Serena defeated Radwanska's sister, Agnieszka, in the Wimbledon final this month.
Top-seeded Roger Federer made only a brief appearance on Centre Court, beating Julien Benneteau of France 6-2, 6-2 in less than an hour to reach the third round.
Routine wins have been elusive at the Olympics for Federer, who is playing in the Games for the fourth time and still seeking his first singles medal. He was pushed to three sets in the opening round but he easily eliminated Benneteau, who held a two-set lead against Federer at Wimbledon a month ago before losing.
Andy Roddick quickly took to Olympic grass, winning his first-round match over Martin Klizan of Slovakia, 7-5, 6-4. As a price for being unseeded, he'll face a daunting challenge in the second round: Novak Djokovic, the 2011 Wimbledon champion.
Top-seeded Victoria Azarenka of Belarus defeated Irina-Camelia Begu of Romania on Centre Court, 6-1, 3-6, 6-1.
Lleyton Hewitt of Australian and Nikolay Davydenko of Russia, both three-time Olympians, won their opening matches. No. 9-seeded Juan Monaco of Argentina, No. 13 Marin Cilic of Croatia and No. 16 Richard Gasquet of France.
Files from the Associated Press were used in this report
Rachel Brady