Slovenia's Primoz Roglic moved into second place, within two minutes of race leader Valerio Conti, by winning stage nine of the Giro d'Italia.
Roglic was 11 seconds ahead of second-placed Victor Campenaerts, with Bauke Mollema a minute off the pace in third.
Conti extended his lead to one minute 50 seconds, with Roglic surging from 12th place more than five minutes back.
Roglic was three minutes 11 seconds faster than Briton Simon Yates, who is five minutes 36 back in 24th overall.
The Slovenian is the man in form this season - having won the Tour of Romandie, the UAE Tour and the Tirreno Adriatico - and is now well placed for a first-ever victory in a three-week tour.
He has an advantage of one minute 44 seconds over two-time Giro winner Vincenzo Nibali going into the event's mountainous section.
Hugh Carthy, riding for EF Education First, is the highest-placed Briton, finishing eighth on the 34.8km stage and moving up to 16th overall.
Stage nine result
1. Primoz Roglic (Slo/Jumbo) 51min 52sec
2. Victor Campenaerts (Bel/Lotto-Soudal) +11secs
3. Bauke Mollema (Ned/Trek-Segafredo) +1:00
4. Vincenzo Nibali (Ita/Bahrain-Merida) +1:05
5. Tanel Kangert (Est/EF Education First) +1:10
6. Chad Haga (USA/Team Sunweb) +1:14
7. Bob Jungels (Lux/Deceuninck-Quick-Step) +1:16
8. Hugh Carthy (GB/EF Education First) +1:30
9. Pello Bilbao (Spa/Astana Pro Team) +1:43
10. Mattia Cattaneo (Ita/Androni Giocattoli-Sidermec) +1:52
General classification after stage nine
1. Valerio Conti (It/UAE Team Emirates) 36hrs 08mins 32secs
2. Primoz Roglic (Slo/Jumbo) +1min 50secs
3. Nans Peters (Fr/AG2R La Mondiale) +2:21
4. Jose Joaquin Rojas (Sp/Movistar) +2:33
5. Fausto Masnada (Ita/Androni Giocattoli-Sidermec) +2:36
6. Andrey Amador (CR/Movistar) +2:39
7. Amaro Antunes (Por/CCC Team) +3:05
8. Valentin Madouas (Fra/Groupama-FDJ) +3:27
9. Giovanni Carboni (Ita/Bardiani-CSF) +3:30
10. Pello Bilbao (Spa/Astana Pro Team) +3:32
16. Hugh Carthy (GB/EF Education First) +6:40
24. Simon Yates (GB/Mitchelton-Scott) +5:36
31. Tao Geoghegan Hart (GB/Team Ineos) +6:58