Roche crossed the line in 26th, seven seconds behind winner Michal Kwiatkowski of Poland with Australia’s Simon Gerrans second ahead of Spain’s Alejandro Valverde.
A crash with just over two laps remaining forced Irish team leader and medal contender Dan Martin to change his bike and he lost contact with the bunch at a time when all three Irish were still in contention.
Martin attempted to fight back on and got very close to the bunch; riding just 40 seconds back for long periods on the penultimate lap. But he finished well down the field while Donegal man Philip Deignan fell back with two laps remaining and was listed as a non-finisher.
On Saturday, Michael O’Loughlin was best of the Irish in the junior men’s road race, the Carrick man coming home in 44th, 1:33 behind winner Jonas Bokeloh of Germany.
Eddie Dunbar and Stephen Shanahan were the only other two Irish finishers and they crossed the line 3:51 and 9:56 down; in 60th and 92nd place.
Both Daire Feeley and Dylan O’Brien’s hopes of doing well were scuppered early on.
O’Brien went down in a crash in the opening five kilometres but he battled to get back on before tailing off on the third of seven laps and Feeley suffered cruel luck too – just like at the European Championships – when he punctured on the opening lap and never managed to get back into the race despite a brave but futile chase.