CONEGLIANO, Italy -- Italian Mario Cipollini claimed his fourth stage win of this year's Giro d'Italia by winning the 15th stage of the race in wet conditions in northern Italy on Tuesday.

The Acqua and Sapone rider claimed the 38th Giro stage win of his impressive career by beating Spaniard Isaac Galvez Lopez of the Kelme team and Italian Alessandro Petacchi of the Fassa Bortolo team to the line in a sprint finish.

German Jens Heppner retained the overall race lead for the tenth day, 48 seconds ahead of Australian Cadel Evans of Mapei.

Heavy rain soaked the riders for most of the 156-kilometer stage from Terme Euganee and because of the dangerous conditions, race judges took the time for the stage when the riders first arrived in Conegliano.

This left the riders free to contest the three laps around the town -- and the sprint finish -- without risking their position in the overall standings.

Cipollini was perfectly guided by his teammates through the rain and then, after carefully coming through the final curve, the big Tuscan powered to the line three bike-lengths clear of his rivals, reported Reuters.

He had also won the first, third and ninth stages of the race.

Today's 16th stage is the first in the dolomite mountains with a finish in the ski resort of Corvara in Badia.

The overall challengers will have to show their climbing skills with four major climbs in the 163km of racing.