Andy Hodge and Katherine Grainger took their fourth career titles at the Great Britain senior rowing trials at Hazewinkel in Belgium.
Hodge (left) and Reed (second from right) beat Williams (right)
World men's four champions Hodge and Peter Reed took the men's pair, while Grainger won the women's single scull.
Hodge and Reed beat fours team-mate Steve Williams and former world junior champion Matt Langridge by six seconds, in a time of 6:27.99.
"Andy was on fire from 750m onwards," said Reed.
"We felt if we went out hard, we could win like we did."
Williams, who won Olympic gold in Athens with Matthew Pinsent, James Cracknell and Ed Coode, clinched the 2006 world coxless four title with Reed, Hodge and Alex Partridge.
"It wasn't that we rowed badly," said Williams. "We just couldn't live with that today."
Twice Olympic silver medallist Grainger got off to a fast start and held on to pip Annie Vernon in a photo finish to win in 7:35.91.
"That's the way I would have wanted to race it," said Grainger. "I like to get out front and then control the race from there."
Alan Campbell, World Cup overall winner last year in his first senior international season, won his second straight men's single scull title in 6:53.85.
The men's and women's lightweight singles titles went to Helen Casey and world champion Zac Purchase in 7:47.34 and 6:56.19 respectively, while Alison Knowles and Natasha Howard won the women's pair in 7:15.54.
The Great Britain team for the first World Cup regatta of the season in Linz, Austria (1-3 June) will be announced in early May.