Last year's overall winner, Stuart O'Grady, of Australia, was disappointed with third place after leading out the final sprint. But Van Bon is one of the world's fastest finishers as he proved by winning a stage of the Tour de France and taking second place overall in the World Cup last year.
Yesterday he was short of team support in the last-lap manoeuvrings, while O'Grady was paced by his Credit Agricole team-mate Magnus Backstedt. Van Bon spotted his opportunity when O'Grady went clear as the leaders swung round the right-hander into Whitehall.
"I managed to get on to O'Grady's wheel with 600 metres to go and he gave me the perfect lead out," he said.
O'Grady's team-mate, Chris Boardman, finished down the field in 33rd place. But as the main pack were all given the same time as the winner, he is still well placed to challenge for the overall lead.
The streets of Westminster were transformed into a racing circuit - complete with barriers and portable grandstands - for the 45-mile stage which took in Whitehall, Northumberland Avenue and the Thames Embankment before finishing a few yards from Downing Street.
Circuit races are often treated as exhibition events, but a major upset looked on the cards when a powerful and determined group of eight riders broke clear after 10 miles of racing. The move, which included overall contenders O'Grady and Hincapie, and Britain's Joe Bayfield and Chris Lillywhite gained 45 seconds lead over the main pack.
The Rabobank team could see the race slipping away from them and their five riders lined-out on the front of the pack, pacing each other in a long, hard chase of the eight leaders.
The rest of the field was happy to be towed along in the wake of the Dutch team which finally caught the breakaway group after a 10-mile chase.
Today the 103 riders left face a 112-mile leg from Rochester to Portsmouth followed by a 4.2-mile time trial at Southsea.
PRUTOUR First stage (London, 45 miles) Leading placings: 1 L Van Bon (Neth) Rabobank 1hr 31min 49sec; 2 G Hincapie (US) US Postal Service; 3 S O'Grady (Aus) Credit Agricole; 4 J Silovs (Latvia) Home-Jack & Jones; 5 D McKenzie (Aus) Linda McCartney; 6 A B Andresen (Den) National team; 7 C Capelle (Fr) Bigmat Auber 93; 8 C Dacruz (Fr) Bigmat Auber 93; 9 C Power (Irl) National team; 10 M Backstedt (Swe) Credit Agricole all same time. Leading overall standings: 1 Van Bon 1:31:36; 2 Hincapie +4sec; 3 O'Grady +7; 4 C Lillywhite (GB) Linda McCartney s/t; 5 P Przyzial (Pol) Mroz +10; 6 Backstedt +12; 7 Silovs +13; 8 McKenzie; 9 Andresen; 10 Capelle all s/t.
n Laurent Jalabert recaptured the Giro d'Italia lead yesterday by two- hundredths of a second from Marco Pantani. The Frenchman clocked 40min 36sec to wipe out Pantani's overnight lead of 55 seconds.