Switzerland's number eight seed Timea Bacsinszky fought her way into her second French Open quarter-final on Wednesday, defeating American veteran Venus Williams 6-2 6-4 in a contest full of see-saw tennis.After dropping the first two games, the eighth-seeded Swiss won eight in a row, controlling the match for long periods from the centre of the court and varying the pace and depth of her play to keep her opponent guessing.Ninth-seeded Williams, playing her 19th Roland Garros and at 35 the oldest player in the women's draw, had strapping on both knees and moved stiffly, especially in the first set, as she gambled on hitting groundstroke winners from often unpromising positions. "I found it hard to get into the match (even though) I had three days to decide on my tactics," Bacsinszky said on court after the match, agreeing it was important to have won in straight sets as "there is no longer any respite" in terms of days off between each match.Bacsinszky, who reached the semi-final last year before losing in three sets to Venus' sister Serena, will play Kiki Bertens of the Netherlands in the quarter-final. ..