Vicky Thornley cruised through her single sculls heat on the opening day of the World Cup 1 meet in Belgrade.
The World Championships silver medallist won by two seconds from German rival Annekatrin Thiele.
The duo were almost 30 seconds ahead of the rest of the finish line to progress to Saturday’s semi-finals.
Fellow Welsh rower Graeme Thomas was part of a men’s quad which edged out Poland to win their heat and qualify for Sunday’s finals.
Preston-born Thomas was joined by Tom Barras, John Collins and Jonny Walton.
The quad are looking this season to better the silver medal it took form the worlds in Sarasota-Bradenton last year.
In the men’s lightweight men’s doubles Cardiff’s Zak Lee-Green and Sam Mottram qualified for the semi-finals from the repechage round.
Results Day 1:
Women’s single sculls (W1x)
1. Victoria Thornley (GBR) 7:54.41
2. Annekatrin Thiele (GER1) 7:56.83
3. Virginia Diaz Rivas (ESP) 8:23.75
Men’s quadruple sculls (M4x)
1. Great Britain (Tom Barras, Jonny Walton, Graeme Thomas, John Collins) 5:53.57
2. Poland 5:54.63
3. Norway 6:00.61
Lightweight men’s double sculls (LM2x)
1. Tim Brys & Niels Van Zandweghe (BEL) 6:37.46
2. Julian Schoeberl & Bernhard Sieber (AUT) 6:39.99
3. Zak Lee-Green & Sam Mottram (GBR1) 6:47.37
Lightweight men’s double sculls repechage
1. Andri Struzina & Julian Mueller (SUI1) 6:34.48
2. Zak Lee-Green & Sam Mottram (GBR1) 6:35.32
3. Fiorin Rueedi & Pascal Ryser (SUI2) 6:36.97