Mahe Drysdale won the men's single sculls for the second successive Games in thrilling fahsion, while the United States continued their dominance of the women's eight.
New Zealander Drysdale added to his gold from London 2012 by narrowly beating Damir Martin of Croatia, despite the duo sharing a time of six minutes and 41.34 seconds.
USA's women's eight have not lost a major championship since 2005 and they triumphed once again at the Lagoa Stadium, Eleanor Logan part of the winning crew for the third Olympics in a row.
Reigning world champion Kimberley Brennan produced a dominant display in the women's singles sculls to top the podium, while Emma Twigg missed out on a medal by finishing fourth in the A final for a second straight Games.
In the men's eight, Great Britain lead after the first 500m and were close to a length clear before the midway point.
Britain saw out a comfortable victory in the final rowing event at Rio 2016, with Matt Langridge finally getting a gold medal after silver in Beijing and bronze at London.
A brilliant line up in the men's single sculls final did not fail to disappoint.
European Champion Martin took a slender advantage in a tight opening 500 metres, opening up the field with reigning world champion Ondrej Synek of the Czech Republic and Drysdale by halfway.
Drysdale took charge from there, but Martin rowed him down in the final 100m and appeared to have done enough to take the gold.
However, with equal times a photo finish showed Drysdale edging the win by the narrowest of margins, and he topped the podium with Synek taking bronze.
QUOTES OF THE DAY
"I had no idea. I got the feeling he just passed me and I just chucked in a few short ones in desperation. It was not the way you want to finish, but to come away with that result was fantastic," - Mahe Drysdale was delighted despite almost seeing his Olympic title slip away.
"I've imagined this so many times. I can stop feeling inadequate. My husband has a gold medal so now we're even," - topping the podium helps Kimberley Brennan feel on a level playing field with husband Scott.
"Fifteen years of rowing, 30 years of family support, and an awesome group of girls who push me every day. No margin is big enough, no stroke is hard enough, but the important thing is we did this together," - five-time world champion Amanda Polk reflected upon her first Olympic medal in the women's eight.