Chris Froome provided the Bastille Day fireworks on the Tour de France's first mountain day with a victory on stage ten to La Pierre-Saint-Martin which distanced his rivals in the race for the yellow jersey.
Team Sky principal Sir Dave Brailsford on Monday's rest day alleged the British squad has been the victim of computer hacking by critics convinced Froome is using performance-enhancing drugs.
Froome, during the 2013 Tour which he won, was subjected to sustained interrogations and his performances were pored over by critics, with some using data to justify their stance.
The 30-year-old Team Sky leader, who has always denied doping, can expect further inquisitions from a public sceptical after years of drug cheats winning the Tour following a stunning win.
He ruthlessly attacked 6.4km from the end of the 167km route from Tarbes to the summit of the first hors categorie (beyond category) climb to surge to a fifth Tour stage success.
The 15.3km ascent averages at 7.4%, but the first two-thirds of the climb was brutal in its gradient, with large sections over nine per cent.
The explosive acceleration left his rivals in his wake as Froome grabbed the race by the scruff of the neck.
Eleven stages remain and this was the first mountain stage, but such was Froome's dominance that his fifth Tour stage win could be decisive in the race to Paris on 26 July.
Froome's Team Sky colleague Richie Porte was second and Nairo Quintana (Movistar), the 2013 runner-up to Froome, was third.
Porte was 59secs behind, Quintana 1mins 04secs and Robert Gesink (Lotto-Jumbo) 1:33 behind.
Alejandro Valverde (Movistar) was fifth, 2:01 behind with Geraint Thomas (Team Sky) on his wheel.
Another Briton, Adam Yates (Orica-GreenEdge), was seventh.
Froome had a 12-second advantage over Tejay van Garderen (BMC Racing) after nine stages.
Alberto Contador (Tinkoff-Saxo) was one minute 3 seconds back, Nairo Quintana (Movistar) 1min 59secs adrift and defending champion Vincenzo Nibali (Astana) 2:22 behind. Now Froome leads the entire race by 2:52 from Van Garderen.
Quintana is now third, 3:09 adrift, Valverde fourth, 4:01 behind, Thomas fifth, 4:03 back, and Contador sixth, another second adrift.
Dan Martin was the best of the Irish in 57th position, with Nicolas Roche 75th and Sam Bennett 165th. Martin is 30th overall, Roche 47th and Bennett 178th.
Pierrick Fedrigo (Bretagne Seche Environnemont) and Kenneth van Bilsen (Cofidis) formed the day's early two-man breakaway.
The pair had a lead of 2:30 when they began the final climb, with Contador's Tinkoff-Saxo and Quintana's Movistar squads driving the peloton.
The main bunch was splintering with every pedal revolution due to the high tempo.
Lampre's Rafael Valls attacked and next Gesink, who began the day 2:52 behind in 15th, went, with the duo passing Fedrigo with 11km to go.
Nibali next lost contact as his bid to successfully defend the maillot jaune loosened further.
Froome had Thomas, Porte and Woet Poels for company, while Quintana had two team-mates alongside, including Valverde.
Team Sky took the initiative to keep the pace high, with Gesink 14secs up the road and Valls caught.
Valverde chose the steepest section to launch his acceleration, but he was swiftly reeled in by the Thomas-led bunch, which had been reduced to a group of around 10 riders.
Contador was losing touch, so Porte ruthlessly pushed on and the Spaniard lost total contact.
Next Van Garderen fell back and then Froome accelerated alone, Porte's work done.
Quintana was left behind as Froome broke away 6.4km from the summit and next passed Gesink in a dominant display.