Coleraine rowing brothers Richard and Peter Chambers impressed in winning their lightweight fours heat at Eton Dorney on Saturday.
Germany led in the early stages of the race but the Team GB crew took control after 500m and cruised to victory.
Britain's time of 5:49.29 was the fastest of the three heats and they go through to Tuesday's semi-finals.
Another Coleraine man
Alan Campbell also comfortably progressed
as he won his single sculls heat.
Campbell powered clear over the opening 500 metres and his finishing time of 6:47.62 left him more than three seconds ahead of second-placed Chinese rower Zhang Lang as he qualified for Tuesday's quarter-finals.
The Northern Irishman has struggled to produce his best form this season and had to settle for a disappointing third in a relatively weak field at the Munich World Cup regatta.
However, Campbell was won medals at the last three World Championships and will hope to reproduce that kind of form at Eton Dorney.
The British lightweight fours team established themselves as early favourites for gold after beating world Australia and Germany in their heat.
The GB quartet have finished on the podium in each of the three World Cup events this season and took victory at the most recent regatta in Munich.