Instant-Dict coach Koo Luam-khen said they were defeated by one man - Carlos Dunga.
Koo made his comment after Instant's 3-0 defeat by Jubilo Iwata in last night's Asian Club Championship first round, first-leg tie.
'Dunga scored with a spectacular free-kick in the first half and caused the referee to send one of our men off in the second half,' said Koo.
'If we had 11 players until the end, the result could have been different.' Instant-Dict defender Chan Chi-kwong was given his marching orders after a second bookable offence in the 58th minute when he tackled Dunga.
'I think Dunga cheated and the referee believed him,' Koo added.
Jubilo Iwata coach Valmir Louruz backed the South Korean referee on Chan's sending-off.
But Louruz said: 'I don't think the referee could see what had happened.