After 105 miles of racing through the hills of South Wales, the leaders were confronted by the towering Constitution Hill. As the riders zig- zagged to stay upright on the 30 per cent gradient, the Lithuanian emerged from a 20-man group to crest the summit with a lead of 30 metres. The finish was only a mile away - all downhill - and Rumsas descended safely to take the stage by six seconds from Jens Voigt of Germany.
Britain is unknown territory for Rumsas, who finished ninth in last year's world championship road race and has won in France and Italy this year.
"My manager had warned me about Constitution Hill," he said, "and I'd been waiting for it all day."
Rumsas played down his prospects of taking the overall lead. "My team is under strength, we've only got four riders instead of six, so the best I can hope for is perhaps two stage wins."
The toughest stage of the race had been expected to see the end of the Luxembourger Benoit Joachim's challenge, but the overall leader clung on to the red jersey despite being stranded in the second group on the road with 25 miles to go. "I thought I'd lost the leadership, because I'd only got one team-mate, George Hincapie, with me. I've George to thank for chasing hard, and getting me back into contention," he said.
Benoit's leading margin was reduced to two seconds over Marc Wauters of Belgium. "This race is going to be decided by sprint bonuses, it's going to be very hard to defend the jersey," he added.
A stage that featured four first-category climbs started with an attack from two avowed non-climbers, the Australian Jay Sweet, a sprint finish specialist, and the Swede Magnus Backstedt, who at 6ft 4in has a lot of weight to haul up the hills.
They rapidly gained ground on the main pack in which the leading contenders were happy to save themselves for the decisive climbs in the last 40 miles. Their lead grew to nine minutes as they shared the pace over the two- mile climb of the Tumble, near Abergavenny. They were still together on the Rhigos climb at 67 miles, but the main pack accelerated, and they were caught by a 10-man chasing group on the Bwlch hill after 79 miles of freedom. The leading group had grown to more than 20 riders by the time it reached Swansea, and Rumsas pounced.
Chris Boardman played a team role and was happy to finish 18th on the stage and move to 13th overall after working to help Voigt, his Credit Agricole team-mate, take second place.
Today the riders face the longest stage of the tour, 132 miles from Swansea to Birmingham.
n Mario Cipollini won a battle of leading sprinters yesterday by holding off Ivan Quaranta and Jeroen Blijlevens to claim the 12th stage of the Giro d'Italia to Sassuolo, in the Tour of Italy. Cipollini edged home at the finish following a 168km ride, mostly on the flat, from Cesenatico. Laurent Jalabert, who finished in the main bunch, retained the overall lead, four seconds ahead of the defending champion, Marco Pantani.Reuse content