Britain's rowing team scored key victories during Monday's heats and repechage races - where first-round losers are given another chance to qualify - at Rodrigo de Freitas Lagoon, a day after windy conditions scuttled events.
Britain secured a semi-final spot in the men's four, an event in which it snagged gold at the London 2012 Games, while the women's eight booked their berth to a finals showdown against a dominant United States crew.
Women's eight rower Zoe de Toledo said her Britain crew demonstrated exceptional commitment in their path to Rio.
"You can't underestimate the dedication and the sacrifice that goes into this kind of performance," de Toledo said on Monday. "That's what the Olympics are about."
Rio 2016 Olympic Games Moments - In pictures
Britain was second in the points table in the World Rowing Cup series coming into the 2016 season, behind New Zealand, whose men's pair Eric Murray and Hamish Bond continued their seven-year unbeaten streak Saturday, winning their heat in the event.
Britain's men's eight also won their heat on Monday, securing a spot in the final.
British women's pair Helen Glover and Heather Stanning, meanwhile, paddled into a spot in the semi-finals, narrowly avoiding a break in their five-year unbeaten streak by mere fractions of a second against a surging Denmark.
Monday's action unfolded after a rocky start this weekend to this year's Olympic rowing.
Unruly winds on Saturday created challenging conditions for rowers, capsizing a Serbian boat, sparking anger among some competitors that the kick-off events were not postponed.
Continued blustery conditions forced organizers to postpone Sunday's rowing races.
Read More
MORE ABOUT