BAGNÈRES-DE-LUCHON, France (VN) — Two years ago, Nairo Quintana attacked over the snow-shrouded Stelvio summit to eventually win the 2014 Giro d’Italia.

On Saturday, across the sunbaked Pyrénées, it was Quintana who was uncharacteristically asleep at the wheel, opening the door for Chris Froome (Sky) to attack on the final descent to the line.

“I let my guard down,” Quintana admitted as he sat on the step of the Movistar bus. “I don’t expect this to prove decisive.”

Froome’s electrifying downhill attack off the Col de Peyresourde late in the four-climb stage sent shockwaves through Movistar. Quintana’s near-perfect Tour de France was turned upside down when Froome attacked over the top of the summit just as Quintana was reaching for a water bottle.

Movistar captain Alejandro Valverde chastised his younger teammate for letting his guard down against the always-dangerous Froome. Valverde said he was slightly gapped following a flurry of attacks from the GC group heading to the summit, and that Quintana simply should have followed Froome’s wheel, rather than waiting for Valverde to regain contact.

“When we got over the top, I realized that Froome was opening up a gap,” Valverde said at the finish line. “I don’t know why Nairo didn’t follow. I was already back, and it was obvious that I wouldn’t be able to get back to the front. He should have been right on Froome’s wheel.”

Valverde also criticized other GC riders for not helping to chase Froome on the fast, 13.5-kilometer descent.

“When I started to work, it was already too late and it was complicated to cut the gap to Froome,” Valverde said. “Everyone here wants to win the Tour, but it’s always the same ones who end up pulling. … And to make it clear once more, I am here to help Nairo, and that’s what we’re doing.”

Until Saturday’s high-altitude hiccup, Quintana seemed to be firmly in control of the stage. When the sparks finally started to fly on the Peyresourde, Froome opened up a few flares, and each time, Quintana was right on his wheel. As the reduced GC group eased toward the top of the climb, Quintana reached over to grab a water bottle. With temperatures pushing into the 90s, Movistar had wisely put a soigneur at the top to hand up bottles.

“I was reaching over for a water bottle to refresh myself, and Froome took advantage of this moment to attack,” Quintana said. “He went down, and got away from us, and took some seconds on all of us. I thought we could catch him on the descent, and Alejandro [Valverde] pulled hard, but it wasn’t enough. These are only the first mountain stages, and tomorrow will certainly be more decisive. I still have a lot of confidence.”

The lapse was a rare mistake from Quintana, who is rarely caught unawares in the key moments of a race.

“I’ve never seen Froome attack like that. It was something spectacular, but it’s also our obligation to be paying attention,” said Movistar boss Eusebio Unzué. “We hope that’s not the difference when we get to Paris.”

Movistar’s riders are also kicking themselves, especially after they safely shepherded Quintana across the flats to deliver him on equal time to Froome going into the mountains. Now going into the decisive Arcalis summit finale Sunday, Quintana is 23 seconds back.

“You always have to be paying attention, and when you’re not, you pay for it,” said Movistar sport director José Luis Arrieta. “Every second counts, because we’ve seen how close the Tour can be. At the same time, we don’t have to go crazy. Tomorrow is a big day, and everyone will be tired because we’ve done a lot of kilometers. If there is a key moment, Nairo will be there.”