Sam Querrey defeats Gilles Simon to reach Nottingham semi-finals

Sam Querrey came from a set down to knock out second seed Gilles Simon and reach the semi-finals of the Aegon Open in Nottingham on Thursday.

Simon had won four of his previous five meetings with the big-serving American and looked on course to record another victory early on in Nottingham.

But 12th-seeded Querrey fought back from losing the first set and, aided by 26 aces, he overcame the challenge of Simon 5-7 7-6 (10-8) 6-4 in just over two hours.

Querrey is now the only seed left standing after number four Leonardo Mayer was also sent crashing out at the quarter-final stage, beaten by Denis Istomin.

Argentinian Mayer had been pushed hard by Jiri Vesely in the last 16 before winning 7-6 (7-2) 7-6 (7-5), but he could not repeat the feat in another hard-fought clash against Istomin.

Mayer fashioned a match point but Istomin survived before going on to claim a 6-3 6-7 (8-10) 7-6 (8-6) victory.

Istomin, who saved all seven break points as he held off Mayer, will next face Cypriot Marcos Baghdatis, who had a much easier time earlier on against Simone Bolelli, knocking out the Italian 6-4 6-4.

Baghdatis has yet to drop a set at Nottingham and beat top seed David Ferrer in the second round.

Alexandr Dolgopolov completed the semi-final line-up, with the Ukrainian battling past Lu Yen-hsun of Chinese Taipei 6-4 4-6 7-6 (7-4) in their quarter-final clash.