Chris Froome waited in vain for his rivals to make a move as Jarlinson Pantano won stage 15 of the Tour de France.
The 160 kilometre stage from Bourg-en-Bresse to Culoz saw just a handful of half-hearted attacks against the yellow jersey and Team Sky were able to cover them to keep Froome almost two minutes clear overall.
Colombian Pantano of IAM Cycling collected his first career Grand Tour stage win by outsprinting Tinkoff's Rafal Majka as the last two survivors of a 30-man breakaway scrapped over honours on the day, but behind there was little action in the general classification fight as another opportunity for Froome's rivals passed by.
"I'm surprised there weren't more attacks today because it was a perfect opportunity to really put us under pressure," Froome said. "I did expect more to be happening but it was such a hard day not many people had the legs there."
Froome crossed safely in a much-reduced peloton a little over three minutes after Pantano, and the Team Sky man remains one minute 47 seconds clear of Trek-Segafredo's Bauke Mollema in second, with Briton Adam Yates of Orica-BikeExchange still third, two minutes 45 seconds down and leading the young riders' classification.
Dan Martin remains in ninth, five minutes and three seconds behind Froome.
After the riders tackled the hors categories Grand Colombier, they crossed the finish line for a first time in Culoz and doubled back to go up the other side of the mountain and it was there, on the Lacets, that a handful of contenders tried their luck.
Astana's Fabio Aru was the first, followed by Quintana's team-mate Alejandro Valverde, and then AG2R La Mondiale's Romain Bardet.
But each time Froome's Sky team-mates just increased the pace at the front of the peloton and methodically reeled them back in without Froome having to do the work.
"I really am in such a privileged position to have such a strong team around me," Froome said. "It may be the strongest team Sky has ever put in the Tour de France and these are guys who would be leaders in other teams in their own right.
"It must be quite demoralising for other people to have to think of attacking knowing this calibre of riders will be chasing them down."
Yates had appeared to be hanging on for much of the day, but stayed with the leading contenders to remain 14 seconds clear of fourth-placed Quintana.
"I wasn't super today but I also wasn't bad," the 23-year-old said. "It was another strong showing from Sky, the rode a real hard tempo on that last climb. What more can you do?
"We're another day closer to Paris and happy with where we are."
The profile invited a breakaway and when it went it was big, with 30 riders including Giant-Alpecin's Tom Dumoulin, winner of two stages in this year's Tour already, Giro d'Italia winner Vincenzo Nibali (Astana), Pierre Roland of Cannondale-Drapac, and Direct-Energie's Thomas Voeckler in their number.
It began to splinter on the first approach to the Grand Colombier, with Majka going clear with Ilnur Zakarin of Katusha.
They were caught by Pantano and Etixx-QuickStep's Julian Alaphilippe on the descent before the latter went away only to crash.
Majka went solo on the Lacets but almost went over the edge on the descent, allowing Pantano to bridge over, and it was the Colombian who had the legs when the two sprinted to the line.
"This is incredible," the 27-year-old said. "It's a dream come true. I came to the Tour de France for that but I didn't believe it could happen. I'm very happy."
With Monday's 209km stage 16 from Moirans-en-Montagne to Berne relatively flat, Froome will be looking forward to Tuesday's rest day in Switzerland after an unusual week on the Tour, capped by those bizarre images of him running up Mont Ventoux on foot following a crash on Thursday.
The 31-year-old has been able to see the funny side now, tweeting videos of Sky team principal Sir Dave Brailsford mocking his running style.
"They're taking the mickey now and deservedly so," he said. "It was quite a chaotic moment up there... I was just over a kilometre from the top with no spare bike, they were stuck behind the other riders so I just figured the best thing to do was keep going forward."