Wiggins fell back as the feared Monte Zoncolan took its toll
Bradley Wiggins dropped out of contention in the Giro d'Italia after a brutal day in north east Italy.
Stage 15 finished on the top of the feared Monte Zoncolan after a 10.1km climb with an average gradient of 11.9 percent, and a maximum of 22 percent.
Sky rider Wiggins finished 25 minutes 32 seconds behind stage winner Ivan Basso to drop to 23rd overall.
"Bradley didn't feel too good - maybe yesterday took a lot out of him," Sky boss Sean Yates told their website.
Wiggins had climbed to seventh in the general classification on Saturday but Yates said the Tour de France was always the main target for the three-time Olympic champion.
"That's it for him on the general classification but as I said yesterday the climbs in the Giro just do not suit him," added Yates.
"The one today up Monte Zoncolan was so steep that it was almost bordering on the ridiculous.
"The climbs in the Tour de France are very different and we've got to keep looking at the bigger picture - that race is Bradley's ultimate goal.
"There was no point in breaking it or pushing him any further in this race."
Italian Basso produced a dominant display to win stage 15 by 1:19 from Australian world champion Cadel Evans and jump from 11th to third.
The Liquigas rider is now just over three and a half minutes behind race leader and team-mate David Arroyo.
Basso is now the favourite to take the race victory
Arroyo finished 3:50 down in 11th but has extended his lead to 2:35 over Richie Porte of Team Saxo Bank in the general classification.
However, while he still has over three minutes to make up, Basso has shown he is a stronger climber than both Arroyo and Porte, and several more mountain stages are still to come before the race ends in Verona next weekend.
Basso, the 2006 Giro winner, pulled away from the exhausted Evans with four kilometres to go to the finishing line on the summit after the punishing climb.
Hundreds of thousands of fans lined the tight lane up the famous mountain with one spectator unveiling a banner reading "Welcome to the Gates of Hell" as temperatures soared.
Basso, banned for two years for attempted doping in 2007, was put in a good position by strong work from his Liquigas team as other riders struggled to even turn the pedals given the gradient.
Manuel Belletti, who won the 13th stage, pulled out of the race alongside a number of sprinters with three tough climbs and the Zoncolan proving too much on the 222km (138-mile) route from Mestre, near Venice.
Monday is the final rest day before another mountain stage on Tuesday with a 12.9km individual (eight-mile) time trial from San Vigilio di Marebbe to Plan de Corones.
Stage 15 result:
1. Ivan Basso (Italy / Liquigas) 6hrs 21mins 58secs
2. Cadel Evans (Australia / BMC Racing) +1:19"
3. Michele Scarponi (Italy / Androni Giocattoli) +1:30"
4. Damiano Cunego (Italy / Lampre) +1:58"
5. Alexandre Vinokourov (Kazakhstan / Astana) +2:26"
6. Carlos Sastre (Spain / Cervelo) +2:44"
7. Vincenzo Nibali (Italy / Liquigas) +3:07"
8. Marco Pinotti (Italy / HTC - Columbia) +3:20"
9. Daniel Martin (Ireland / Garmin) +3:31"
10. John Gadret (France / AG2R) +3:45"
1. David Arroyo (Spain / Caisse d'Epargne) 67hrs 48mins 42secs
2. Richie Porte (Australia / Saxo Bank) +2:35"
3. Ivan Basso (Italy / Liquigas) +3:33"
4. Carlos Sastre (Spain / Cervelo) +4:21"
5. Cadel Evans (Australia / BMC Racing) +4:43"
6. Alexandre Vinokourov (Kazakhstan / Astana) +5:51"
7. Vincenzo Nibali (Italy / Liquigas) +6:08"
8. Michele Scarponi (Italy / Androni Giocattoli) +6:34"
9. Linus Gerdemann (Germany / Milram) +7:12"
10. Robert Kiserlovski (Croatia / Liquigas) +8:13"
23. Bradley Wiggins (England / Team Sky) +28:14"