Nairo Quintana described his 3min 37sec lead over Chris Froome at the Vuelta a Espana as a "big difference" and hinted he will ride the rest of the race on the defensive.
Quintana gained 2min 43sec on Froome on stage 15 by joining a surprise 15-man breakaway initiated by Alberto Contador just 6km into the 118.5km day.
The Colombian had earlier stated he would need a lead of at least three minutes going into stage 19's 37km individual time trial to beat Froome and now accepts the race is his to lose.
He said: "My team helped me out so much. I was screaming to them, 'Full gas, full gas, we're leaving Froome behind'.
"We opened a gap, we kept it high and at the final climb, I gave everything to keep Chris well behind. Fortunately, I have opened the gap I considered I needed before the time trial.
"I hope to have the red jersey now all the way to Madrid. The gap now to Froome is a big difference. There is a long way to go yet, and I have to be very careful.
"I'm not too scared of anything. I've got a lot of respect for that time trial, although hopefully it won't be too unfavourable and I will play a defensive game on the mountain stages to come."
Contador lost 37 seconds to Quintana after being dropped by the Colombian on the climb to the summit finish at Aramon Formigal but was rewarded for his earlier attacks with a promotion to fourth place overall.
He said: "I wasn't so optimistic at the start because the climbs didn't seem that difficult, but I attacked like crazy at the start. I didn't even know who was on my wheel and I knew that it was a dangerous bet, but look at what happened.
"The nice thing is we re-wrote the script. We don't have a big strong team like Movistar or Sky, so we had to look for allies."
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.