Italy's Michele Scarponi won the 18th stage of the Giro d'Italia on Thursday with Russia's Denis Menchov retaining his narrow overall lead.
Diquigiovanni rider Scarponi triumphed in a sprint finish following the 182-km route from Sulmona in central Italy.
The 29-year-old, who won the sixth stage earlier this month and the Tirreno-Adriatico race in March, looks in fine fettle having returned from an 18-month ban for his involvement in Spain's Operacion Puerto doping scandal.
Rabobank's Menchov, who denied involvement in a different doping affair on Wednesday after Austrian investigators contacted his team, remains 26 seconds ahead of Danilo Di Luca in the general classification with three stages left.
Riders have said Friday's 164-km stage from Avellino to Mount Vesuvius near Naples will be crucial to the outcome of the three-week race, which finishes with a time trial in Rome on Sunday.
Liquigas rider Franco Pellizotti is two minutes behind Menchov in third and 2006 winner Ivan Basso, back in the Giro after his two-year ban for involvement in Puerto, is 3:28 adrift in fourth and needs something special on the slopes of the famous volcano.
Last year's Tour de France winner Carlos Sastre lies just behind Basso in fifth.
American Lance Armstrong, gaining fitness for a tilt at an eighth Tour title in July after coming out of retirement, is in a creditable 12th position overall but is out of contention 12:17 back.
Ireland's Philip Deignan finished 21st and is 55th overall.
