Sing Tao's Ian Muir sent holders South China crashing out of the FA Cup after scoring the only goal - a 108th-minute, sudden-death winner - in their quarter-final at the Siu Sai Wan Stadium. Former Tranmere Rovers marksman Muir struck his eighth goal of the season yesterday, sweeping home from close range after defender Pau Ka-yiu had picked him out with a cross three minutes into the second half of extra-time. 'We just had to keep going and we needed to keep discipline. We deserved to win. 'The chances were coming but we were not sticking them in [until we scored],' said 34-year-old Muir, Rovers' all-time leading goalscorer. Sing Tao stayed on course for a fourth trophy in nine months, having won the pre-season Regional Council Cup, the President's Cup and more recently the Viceroy Cup. The result left South China, the territory's best-supported club, to concentrate on the league title as they contemplated only their fourth domestic defeat of the season. South China's hopes of winning their first league title since 1992 are fragile, especially as they must win the second phase of the championship to force a grand final with first-phase champions Instant-Dict. Try as they might, South China just couldn't find the net, even though they enjoyed better possession and constantly stormed the Tigers' defence in the closing minutes of the game. It was also sweet revenge for Sing Tao, who last month were denied a league victory in controversial circumstances, South China pinching a point with an Au Wai-lun equaliser eight minutes into injury time. The omens didn't look good for South China yesterday when they lost veteran defender and captain Ku Kam-fai in the seventh minute through injury. Portuguese defender Daniel Dias, a former Guangdong player, was then thrown into the fray for the injured Ku, but South China didn't have the same robust look about them. The Caroliners had to thank Dutch goalkeeper Werner Kooistra for keeping a clean sheet in a first half dominated by Sing Tao. Kooistra first kept out a Lo Kai-wah effort, before being forced to palm away a John Moore follow-up shot in the 17th minute. The big Dutchman came to his side's rescue again after 27 minutes, smothering Wai Kwan-lung's effort after the Hong Kong international was sent free down the middle with the goal in sight. Sing Tao created more opportunities, including one in the 32nd minute when Wai spotted Kooistra off his line - only to curl his effort away from the right-hand post. South China had a more enterprising second half, and came close to scoring in the 75th minute when Muir stopped an angled shot from Hong Kong international Dale Tempest on the line. Tempest watched another effort sail over the bar at the end of a fine move which saw chances fall to winger Lee Kin-wo and forward Ricky Cheng Siu-chung in the last minute of normal time. But Muir killed off South China's hopes with his 'golden' goal, which put his team through to Saturday's semi-final against Uhlsport-Rangers.