On the first day of action in the men's event on the state-of-the-art all-glass court at the Albert Hall in Nottingham, Finnish qualifier Olli Tuominen caused the biggest upset of the day when he despatched sixth-seeded Malaysian Ong Beng Hee in straight games.

Botwright's win was a fitting celebration for the unseeded 26-year-old from Manchester who rose one place to a career-high No13 in the October world rankings.

"That was the best win of my career, without doubt," said Botwright, who has been able to take full advantage of the new National Squash Centre in her home town, where she trained for three solid months over the summer. "It was the longest period of intense training I've ever done, since when I've been desperate to play a tournament."

When asked to describe the difference between her and her fifth-seeded opponent's styles of play, Botwright explained: "Vanessa tends to float the ball about, whereas I'm more of a 'smack-it-and-run' kind of person."

Botwright now meets Australia's third seed Rachael Grinham, who defeated England's Fiona Geaves 9-2 9-2 9-6. The 35-year-old from Gloucester, who yesterday won the Women's Over-35 title, was celebrating her 20th successive British Open appearance.

England's Linda Charman, the world No4 from Eastbourne, had the easiest ride through to the women's quarter-finals when her opponent Jenny Tranfield, the world No10 from Milton Keynes, withdrew from the tournament following a warm-up session on the courts in the morning which made her physically sick. "I've had a viral problem for the last two weeks and woke up this morning with swollen glands and a high temperature - but until I got on court, I didn't know whether I would make it or not.

Olli Tuominen's 15-11 15-10 15-7 win over two-times British Open quarter-finalist Ong Beng Hee was one of the best of his career. The 24-year-old from Helsinki is enjoying a good run on the PSA Tour despite having slipped to 30 in the world from a career-high No16 last August.

"I started really well and ruled the first game, but in the second he got more of the hang of it," said the flying Finn. "He tried to slow the pace down in the third but I was able to concentrate more and volley more. I was nervous because I could see he was tired."

Tuominen will face world champion David Palmer after the second seed from Australia disposed of Egypt's unseeded Amr Shabana 15-12 15-9 15-8 in 46 minutes.

Australia's Anthony Ricketts became the first to claim a place in the quarter finals when he beat English qualifier Nick Taylor, from Manchester, 17-16 15-6 15-8 in 47 minutes.

His opponent in Friday's quarter-finals will be Australian-born Scot John White, who ended Pakistani interest in the event with a 15-11 15-3 17-15 defeat of world No15 Mansoor Zaman. White, who today rose to a career-high No2 in the world rankings, is enjoying competing in his first major international event within five minutes of his Nottingham home.

"It's been great to be able to have a family lunch at home, then wander up to the court to practise, then get back home in time to put the kids to bed, and still be back in time to play my match," said a relaxed White. "There's an incredible squash community here in Nottingham, with loads of juniors and keen players involved with this event, so it's a real treat to be playing the British Open here."