Summer Mortimer has her second gold medal of the London Paralympics, and once again she won in record style.

The Hamilton native won the women's S10 backstroke in a world-record time of one minute 5.90 seconds.

Mortimer also won gold in the 50-metre freestyle event in world-record time last week.

"This feels absolutely amazing," said Mortimer, who also won a silver medal in the 200 individual medley earlier at the Games. "I haven't been that fast since I was abled bodied. To be able to beat my times from when I was 14,15 years old is amazing. I wasn't expecting it but the race went perfectly."

Sophie Pasco of New Zealand, who led Mortimer by a half second at the turn, took the silver in 1:06.69.

"I need to see the clock when I swim backstroke, and I saw that Sophie was ahead of me at the split and I just went for it," Mortimer said.

Shireen Shapiro of South Africa was third in 1:09.02 while Aurelie Rivard of St-Jean-sur-Richelieu, Que., was fifth.

Mortimer ranked third in the preliminaries, but said she was simply following her game plan.

"I went easy in the prelims," she said. "I was trying to strategically place myself a couple of lanes over so I wouldn't be beside the main people and be able to focus on my own race."

The S10 classification is defined as minimal physical impairment. Mortimer broke most of the bones in her feet in a trampoline accident in 2008.

Elsewhere in the pool, Benoit Huot of Montreal won bronze in the men's S10 backstroke in 1:00.73.

"It wasn't easy but it worked out well for me," said Huot, now with 18 career Paralympic medals through four Games. "This isn't the race I feel the most comfortable in and at the end I wasn't sure I was in the medal contenders. I was really hurting in the last 25 metres."

Justin Zook of the U.S., won the gold medal in a world record 1:00.01. Former world-record holder Andre Brasil of Brazil was second in 1:00.11

Canada now has 16 medals (four gold, seven silver, five bronze) over seven games of competition. Canada sits 16th in the gold-medal standings and 13th on the overall medal table.

In women's wheelchair basketball, Canada got off to a strong start in its quarter-final against the United States before falling 67-55.

Canada led 21-10 after the first quarter, but the U.S. narrowed that lead to 33-29 by halftime. The Americans continued to outscore Canada over the third and fourth quarters, turning a tight game into a comfortable win.

Jaent McLachlan of North Vancouver, B.C., led Canada with 31 points and 13 rebounds — both game-highs.

In women's goalball, Nancy Morin of Longueuil, Que., scored the game's only goal as Canada beat the United States 1-0. Canada improved to 3-1 and will play Finland in the quarter-finals on Wednesday.

In sailing, Paul Tingley of Halifax finished second for the second race in a row in the single-person keelboat event. Tingley, a gold medallist in Beijing four years ago, is fourth overall with three races to go.

Victoria's John McRoberts and Stacie Louttit were also in fourth after eight races in the two-person keelboat after finishing third in Tuesday's race.

Also Tuesday, it was announced that Canada would host the 2013 International Paralympic Committee swimming championships. The host city has not yet been selected.

Boccia bronze for Canadians

Canada also picked up a bronze medal in boccia on Tuesday.

Marco Dispaltro of St-Jerome, Que., and Josh Vander Vies of Vancouver defeated British brothers Stephen and Peter McGuire 8-2 in the bronze-medal match of the BC4 mixed pairs category.

The Canadians scored four points in the first end and added four more in the third.

"It feels so good," said Vander Vies. "In the third end, when we scored four points, I knew we would win the match."

It's the first Paralympic medal for Vander Vies and Dispaltro and Canada's first ever in the BC4 division.

"I was in my zone today," said Dispaltro. "We played strong, we played fast and it worked out."

Vergeer extends win streak to 468

After more than 13 years at No. 1 in the wheelchair tennis rankings and going unbeaten since 2003 with 465 consecutive victories, Esther Vergeer entered the London Paralympics with a solid argument for being the most dominant athlete within a single sport.

The 31-year-old Dutchwoman extended that run to 468 matches with a 6-1, 6-0 win against Thailand's Sakhorn Khanthasit in Tuesday's quarterfinals.

It is widely believed that only Pakistani squash great Jahangir Khan has had a longer run of consecutive wins — 555 — but that was across five years, from 1981-86. Vergeer's run has taken more than nine years.

Former Wimbledon champion Richard Krajicek calls his compatriot "perhaps the most successful sportsperson of all time" and it's hard to argue.

"It's not a motivation itself to get to that 555 mark," Vergeer told The Associated Press at Eton Manor, a purpose-built Paralympic venue situated toward the north end of the Olympic Park in east London. "But of course I'm still trying to improve myself, I'm still trying to develop the game of wheelchair tennis.

"If it comes along with it that I win matches, maybe in a few years I'll come close to the 555. But then again there's a lot of girls who work really hard and they are right behind me. I know that. It could be any day that I lose."

The numbers Vergeer has put up since 1996, when she made her first international appearance, are staggering.

She has won 42 grand slam titles (21 singles, 21 doubles) and five Paralympic golds (three singles, two doubles). From 2004-06, she won 250 straight sets. In total, she has won 162 singles titles. And the game she lost against Khanthasit was the only one she has conceded at this Paralympics in three matches.

"My winning run brings a lot of pressure with it," said Vergeer, who has been in a wheelchair since she was 8, when an operation to correct hemorrhaging around her spinal cord left her paraplegic. "Every time I go on court a lot of people have that expectation, and that puts pressure on me. I think it will be good for the game if I lose one day, because that will mean the competition is getting stronger and that there are more girls playing at a higher level."

Vergeer is not only ahead of her rivals in terms of power, being able to fire down serves at speeds of 125 kilometers per hour (78 mph), and technique, in which her dismissive backhand is similar in style to that of Roger Federer.

She is also way ahead in terms of technology.

"Quickie," the name of the wheelchair she uses during matches, is new for the London Games and has a radical design in which Vergeer's legs and knees are locked together and tucked into a device she calls a "bucket" under the chair. In fact, it looks more like a trolley, with two wheels at the front and back. Most competitors just have one wheel at the back and their legs are apart and at right angles.

"It's totally built around me, molded," a proud Vergeer said of her contraption. "I designed it because I think in a regular chair, with a square bucket, you make a lot of movements with your hips and knees, up and down and forwards and backwards. You lose a lot of energy with that, and a lot of placement and pace.

"It's not comfortable — when I finish training or a match, it's a relief — but it works. It makes me very stable, it makes feel very strong on the court."

Vergeer, who has four sponsors to allow her to be a full-time tennis player, has a threatening and aggressive demeanor on court, where she constantly circles around in her chair ahead of receiving a serve. Never still, her reaction times are rapid and, as is to be expected from a long-time No. 1, she is a quick thinker on court.

In Tuesday's searing heat, which forced volunteers and officials to duck for cover from the sun behind the large grandstands on Centre Court, there was no hiding place for Khanthasit from Vergeer's punishing strokes.

That delighted the contingent of Dutch fans in the crowd, who wore orange T-shirts and sang songs throughout. They included her parents and brother, who hugged her as she came off court.

"Is there a secret to my success? I don't know," Vergeer said. "There's a lot of combinations and aspects that make me play well — hard work, determination, just a love of the game of tennis.

"I love to see how far I can go as myself, trying new things. And the team around me just give me all these things to try out and work on — physical, technical, tactical, equipment, nutrition, all those things. As long as I love the game, I'll continue playing."

That spells bad news for her opponents. The last rival to come close to beating Vergeer was countrywoman Korie Homan, who had a match point in the 2008 Paralympic final in Beijing but lost 6-2, 4-6, 7-6 (5).

Homan is retired now, leaving a host of up-and-coming players from the Netherlands to try and achieve what has so far proved elusive.

Next in line is third-seeded Jiske Griffioen in Thursday's semifinals. Naturally, she is seeking a first win over her training partner.

"I don't know exactly my record against her, and I don't want to search for it either," Griffioen said, laughing. "She's an amazing player and I'm going to have to play my best tennis to beat her, but she has all the pressure on her."