Chris Froome has admitted it will be “extremely tough” to beat Nairo Quintana to overall victory at the Vuelta a Espana after his deficit to the race leader grew to 3min 37sec on stage 15.
Froome failed to join an early 15-man breakaway containing both Quintana and Alberto Contador and went on to lose 2min 43sec to the red jersey.
He still has two summit finishes and a 37km individual time trial left on which to close the gap, but he believes it will now be a tall order.
Froome told ITV Sport: "It's definitely made it a lot more hard now. A minute was manageable; three minutes is going to be extremely tough. But stranger things have happened and we're going to keep fighting all the way.
"It was a tough stage for us, obviously. The guys did a lot of work yesterday, so we weren't as prepared as some of the other teams this morning.
"Obviously, getting caught out there with Contador and Quintana in that early break, that put us on the back foot and we just never recovered.
"Credit to them. They rode a really smart race and they have gained a lot of time today on us."
As well as seeing his gap to Quintana grow, Froome also saw his lead over third-placed Esteban Chaves cut to 20 seconds.
Team Sky principal Sir Dave Brailsford hinted Froome's main priority should now be to consolidate second place.
He said: "Sometimes you have got to take your hat off to people and say, 'Well done'. It was a brave move and it paid off for Nairo and Alberto.
"We have just got to sit there and say, 'OK, let's have a look at it and keep on going'.
"Sometimes in sport you take a punch in the face. You turn around and say, 'Right, OK, six days left of racing, we're still in the same position as we were this morning', and we will keep on going."
The Vuelta continues on Monday with a 156.4km 16th stage from Alcaniz to Peniscola, which should end in a sprint. Find out more about the route in our race guide and follow the action with our live blog from 1pm BST.