New Zealand's Mahe Drysdale kept the gold he won in the men's single sculls in the 2012 London Olympics, while Kim Brennan of Australia followed up her bronze in London with pure gold in the women's competition at the ongoing Rio Games.Drysdale rowed against Damir Martin of Croatia on Saturday in a race so close that both athletes crossed the finish line in the same time of 6:41:34, and only a photo-finish could identify the New Zealander as the winner, reports Efe.Martin, the current European champion, got the silver medal while the Czech Ondrej Synek, who won silver medals at London in 2012 and at Beijing in 2008, got the bronze.Cuba's Angel Fournier Rodriguez came in sixth.Meanwhile Australia's Kim Brennan, bronze winner in the 2012 London Olympics and world champion in 2013 and 2015, confirmed her position as favorite Saturday with a victory in the women's single sculls at the Olympic Games in Rio de Janeiro.The Australian, who crossed the finish line at 7:21:54, was the obvious favorite following the gold medals she won this year in the two Rowing World Cup races.The American Genevra Stone, who ascended the podium in two different Rowing World Cup competitions this year, won silver with a time of 7:22:92, while China's Jingli Duan took bronze with 7:24:13.New Zealand's Emma Twigg, fourth in London and world champ in 2014, again came in fourth after retiring from competition last year and only getting back in training this year.Notably missing from the women's single sculls final was Ekaterina Karsten of Belarus, twice Olympic champion who at age 44 was contesting her seventh Olympic Games but was left behind in eighth place.