The Nottingham champion and Eastbourne quarter-finalist was then broken twice more to leave Martic only needing to win her next three service games.

BBC: Elena Baltacha, Melanie South & Katie O'Brien go out

"I'm dead excited as it's my first time there, " said the man who has been a UK Championship (1999) and LG Cup (2003) quarter-finalist.

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Watson, a quarter-finalist in this year's Australian Open juniors, held the opening game of the second set and broke again to go 2-0 up.

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Liang, the 2008 world quarter-finalist, who recently earned a place in the provisional top 16 rankings, kept battling and won three in a row which included knocks of 61 and a 103.

BBC: Ronnie O'Sullivan through despite wobble against Liang

Earlier Federer survived a loss of form in a scrappy second set before finally coming through in four sets against Robredo, world number 52 and a quarter-finalist in this tournament four years ago.

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Singapore may field three badminton players at the Commonwealth Games who have come from Indonesia, and Hong Kong could have one, in addition to their former world women's singles quarter-finalist Wang Chen, who crossed the border from China to the former British colony.

BBC: Defecting dilemmas for Games

Earlier, Jamea Jackson stunned last year's beaten finalist and eighth seed Jelena Jankovic to book her place in the quarter-finals.

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