The Olympic sailing and canoe waters proved fruitful for Ireland's hopefuls on Sunday after the swimmers' comparative struggles in the morning.
Corkman Peter O'Leary and Dubliner David Burrows lie second in the Star Class after two races after finishing second and sixth in Sunday's races.
Eoin Rheinisch progressed to the semi-finals in the canoe slalom K1 event.
Rheinisch, who has family connections in county Donegal, was fourth in the event in Beijing.
The Kildare man was sixth fastest after Sunday's two runs as he produced a composed performance to be among the 15 qualifiers for Tuesday's semi-finals.
Sailors O'Leary and Burrows finished second behind France's Xavier Rohart and Pierre-Alexis Ponsot in Sunday's opening race in the 11-race series.
The Irish duo took sixth in the second race won by Brazil's 2008 silver medallists Robert Scheidt and Bruno Prada.
British pair Iain Percy and Andrew Simpson finished 11th and second in Sunday's races and are fifth overall.