NAUDERS, Austria (AFP) - Switzerland's Fabian Cancellara of CSC retained the overall lead of the Tour of Switzerland after finishing shortly behind enterprising Italian Alessandro Proni here on Monday.

After a breakaway of over 200km, Proni capped a hard day in the saddle - on the first day in the mountains - to claim a well-deserved victory from stage three.

The Italian's maiden professional win was almost never to be, with Spaniard Xavier Florencio and Kim Kirchen of Luxembourg finishing a close seven seconds behind the 24-year-old.

Proni was part of breakaway group which parted company with the peloton after just 17km of racing. Along with Spaniards Daniel Navarro (Astana) and Luis Pasamontes (Unibet), the trio built a lead of more than 11 minutes on the peloton by the 160km mark.

The three riders were still together after climbing to the summit of the Col de la Fluela, at 2,383 metres altitude, however by that time and with 60km still to race the peloton had closed the gap considerably.

With a group of riders closing in in the final 15km, Proni then attacked at the foot of the final, six kilometre climb and went over the top with only a 10-sec advantage.

That last move proved decisive, and allowed the second-year pro - whose best result to date was a third place overall finish in last month's Tour de Picardie - to finish with time to savour his win.

Cancellara leads Proni by only two seconds, but Switzerland's world time trial champion and former Paris-Roubaix winner may require his team to work somewhat harder in the following days in the mountains if he aims to keep his lead.

Tuesday is another climbing day, albeit of moderate difficulty held over 167.2km between Nauders and Triesenberg-Malbun in Liechtenstein.