document: The Australian rode 13.8km in 14 minutes and 56 seconds at an average speed of 55.446 km/h, with German Tony Martin five seconds behind in second.
  "To wear the Tour de France yellow jersey, it's a dream," Dennis said.
  Team Sky's Chris Froome was 50 seconds back as Steve Cummings placed highest of 10 British riders in 10th.
  Defending champion Vincenzo Nibali was the best performer among Froome's fellow contenders for overall victory at the 21-stage race, which ends in Paris on 26 July,
  Astana's Italian rider finished 22nd, seven seconds ahead of 2013 winner Froome, 15 seconds clear of Spaniard Alberto Contador and 18 seconds ahead of Colombia's Nairo Quintana.
  "It's the longer efforts I've been training for and I'm happy to have that out the way," said Froome.
  British former Olympic champion Chris Boardman set the previous fastest individual average speed over a Tour de France stage with 55.152 km/h at the 7.2km prologue of 1994.
  "Everything went perfectly," said Dennis, who will wear the leader's yellow jersey for the start of stage two on Sunday - a 166km ride along the Dutch coast that is likely to end in a bunch sprint.
  "We went with the tactic of going out early and setting a benchmark and making everyone chase me," the 25-year-old BMC rider added on ITV4.
  Dennis's Swiss team-mate Fabian Cancellara came third with a time of 15 minutes and two seconds, while Britons Geraint Thomas of Team Sky and Alex Dowsett of Movistar came 12th and 13th respectively.
  Cummings, 34, last rode the Tour in 2012 and this year is competing for Team MTN-Qhubeka, the first African-based team to tackle cycling's most prestigious race.
  Meanwhile, Astana's Lars Boom completed the stage despite suggestions he should be withdrawn for failing a test for low cortisol levels, which can indicate abuse of cortisone.
  Stage 1 result and general classification
  1 Rohan Dennis (Aus) BMC Racing Team 14mins 56secs
  2 Tony Martin (Ger) Etixx - Quick-Step +5secs
  3 Fabian Cancellara (Swi) Trek Factory Racing +6secs
  4 Tom Dumoulin (Ned) Team Giant-Alpecin +8secs
  5 Jos Van Emden (Ned) Team LottoNL-Jumbo +15secs
  6 Jonathan Castroviejo (Spa) Movistar Team a +23secs
  7 Matthias Brandle (Aut) IAM Cycling at same time
  8 Adriano Malori (Ita) Movistar Team +29secs
  9 Wilco Kelderman (Ned) Team LottoNL-Jumbo +30secs
  10 Stephen Cummings (Gbr) MTN - Qhubeka +32secs
  Selected others:
  12 Geraint Thomas (Gbr) Team Sky +33secs
  13 Alex Dowsett (Gbr) Movistar Team +36secs
  22 Vincenzo Nibali (Ita) Astana +43secs
  33 Simon Yates (Gbr) Orica GreenEdge +46secs
  39 Christopher Froome (Gbr) Team Sky +50secs
  46 Alberto Contador (Spa) Saxo-Tinkoff +58
  57 Nairo Quintana (Col) Movistar +1min 1sec
  68 Peter Kennaugh (Gbr) Team Sky +1min 08secs
  74 Ian Stannard (Gbr) Team Sky +1min 11secs
  97 Adam Yates (Gbr) Orica GreenEdge +1min 18secs
  123 Mark Cavendish (Gbr) Etixx - Quick-Step +1min 26secs
  180 Luke Rowe (Gbr) Team Sky +1min 54secs
summary: Rohan Dennis rode the fastest individual time trial in Tour de France history to claim victory at the opening stage of this year's race in Utrecht.