The British men's four have smashed the world's best time by four seconds in winning their heat at the Lucerne World Cup rowing regatta.
Andrew Triggs Hodge, Tom James, Peter Reed and Alex Gregory took the lead from New Zealand at the halfway stage and then pulled clear to win in five minutes 37.86 seconds.
The previous world best mark of 5mins 41.35secs was set by Germany at the 2002 world championships. The GB crew qualified for the final but were unaware they had set the record until they returned to the boat house.
"We set out to win our heat and we didn't want to hide away from hard work, even in a heat, if it gave us speed," James said. "The world best time is nice but we're here to beat people and to put in that kind of performance consistently."
A strong tail wind on the Rotsee course contributed to a remarkable six new records being set across the regatta.
One of them was set by the Canadian men's eight, who won their heat ahead of Poland with Great Britain's highly-rated crew relegated to third, and they will face a repechage on Saturday.
"We've seen the high standard here that we expected and we have had a strong morning but not everything has gone our way. There is plenty to play for in tomorrow's semis," said GB Rowing performance director David Tanner.
World champions Anna Watkins and Katherine Grainger, who are unbeaten for two years, cruised through their women's double scull heat to reach Sunday's final.
Olympic champions Zac Purchase and Mark Hunter appeared to be pacing themselves when they finished second in their heat.
Elsewhere, there were wins for the women's pair of Helen Glover and Heather Stanning and Alan Campbell in the single scull, who beat Olympic champion Olaf Tufte to qualify for the quarter-finals.