Last at the 500m mark, he was still only fourth at halfway and second with 500m to go before overtaking Czech Republic rival Ondrej Synek, and winning in 6min 55.150s, 1.9s ahead of Synek.
Other wins went to women's single sculler Emma Twigg, who took the lead at the halfway mark and held off China's Jingli Duan by 1.8s; the never-been-beaten men's pair of Eric Murray and Hamish Bond, who crossed more than 10s ahead of their German rivals; the men's lightweight four and lightweight single sculler Julia Edward.
The lightweight four of James Hunter, Peter Taylor, James Lassche and Curtis Rapley turned in an impressive display, winning in 5:53.810, beating home the fancied Danes by almost two and a half seconds.
The women's quad of Georgia Perry, Lucy Spoors, Sarah Gray and Erin-Monique Shelton did well to nail third, less than 2.5s behind second-placed United States with Germany convincing winners.
Brothers Robbie and Karl Manson turned in a handy display, taking fourth in the men's double scull, in a tight finish in which winners Croatia, Azerbaijan and Australia were covered by less than 1s.
The third and final cup regatta is at Lucerne on July 11-13.