Sir Bradley Wiggins slipped down to joint fifth in the general classification after stage four of the Giro d'Italia, won by Italy's Enrico Battaglin.
Fabio Felline and Giovanni Visconti finished second and third respectively to complete an all-Italian top three for the stage, while their compatriot Luca Paolini retained the overall leader's pink jersey.
Wiggins, the race favourite completed the final climb with his rivals but lost time because of a split in the peloton at the finish. He came in 48th, 17 seconds down, after being caught behind a crash and is now 34 seconds behind Paolini, while Wiggins' Team Sky team-mate Rigoberto Uran moved to second overall.
The Colombian finished fourth in the second-longest stage of the Giro, which took six hours and 14 minutes, including a testing climb up the Croce Ferrata with 12km to go to the finish at Serra San Bruno. The stage was made even more problematic by the wet conditions, which made corners treacherous and threw up spray, resulting in poor visibility. In the final kilometre, a series of curves and cobbled streets only added to the strain on the riders.
Other fancied contenders Cadel Evans of Australia, the Italian Vincenzo Nibali and defending champion Ryder Hesjedal of Canada came home safe after a 246km (152-mile), undulating trek from Policastro Bussentino.
Paolini leads Uran in the general classification by 17 seconds, with Spain's Benat Intxausti in third, 26 seconds off the pace, for Movistar.
Nibali leapfrogged Wiggins into fourth while Hesjedal drew level with the Briton in fifth, 31 and 34 seconds off the pace respectively. Nibali survived a scare with 35 kilometres remaining when he suffered a mechanical problem but managed to get back into the bunch after Astana team-mate Valerio Agnoli gave him his wheel.
"I knew that this finale was tailor-made for me," Battaglin told TV channel BeIn Sport. "I knew it was now or never for me to win a stage."
Wednesday's stage is a mainly flat, 203km (126-mile) leg from Cosenza to Matera, where a sprint finish could result in British rider Mark Cavendish winning his 12th Giro stage.
1 Luca Paolini (It) Katusha 15:18:51
2 Rigoberto Uran (Col) Sky +17"
3 Benat Intxausti (Sp) Movistar +26
4 Vincenzo Nibali (It) Astana +31
5= Ryder Hesjedal (Can) Garmin +34
5= Bradley Wiggins (GB) Sky +34
7 Giampaolo Caruso (It) Katusha +36
8 Sergio Montoya (Col) Sky +37