Geraint Thomas set for Tour de France Victory as Dumoulin wins Time Trial
Tom Dumoulin finishes second and Chris Froome third overall, Dumoulin fastest.
The final 31km decisive final time trial on Stage 20 was rugged, with short climbs and some steep gradients.
All eyes were on Primoz Roglic, Dumoulin and Froome all duelling for podium places.
In the end it was Dumoulin who went fastest, and Froome finished faster the Roglic by 1m 11s, taking back his podium place after losing it yesterday.
Dumoulin said: "That was crazy! I can't believe it. I still thought Froome was one second ahead when I crossed line. It has been an amazing last day, I was so nervous. I had such a hard time yesterday, but today it has just been great to take the stage win."
Geraint Thomas finished comfortably in third place, confirming his overall victory at the 2018 Tour de France, ahead of the precession into Paris, where the sprinters will battle for the final sprint victory of the Champs-Elysées.
Early on it was Michael Hepburn (Mitchelton-Scott) who set the fastest time until Team Sky's Michal Kwiatkowski (Sky) went faster in a time of 41m 42s.
Dumoulin knocked nearly a minute of Kwiatkowsk's time and Froome battled hard to take stage victory, finishing one second won on Dumoulin and Thomas just 14 seconds down.
Geraint Thomas was the first British rider to win a stage finishing on L'Alpe d'Huez.
VIDEO: 2018 Tour de France Stage 20 Summary
2018 Tour de France Stage 20 Top 10
1 Tom Dumoulin (Ned) Team Sunweb 00:40:52
2 Chris Froome (GBr) Team Sky 00:00:01
3 Geraint Thomas (GBr) Team Sky 00:00:14
4 Michal Kwiatkowski (Pol) Team Sky 00:00:50
5 Søren Kragh Andersen (Den) Team Sunweb 00:00:51
6 Bob Jungels (Lux) Quick-Step Floors 00:00:52
7 Ilnur Zakarin (Rus) Katusha-Alpecin 00:01:02
8 Primoz Roglic (Slo) LottoNL-Jumbo 00:01:12
9 Marc Soler (Spa) Movistar Team 00:01:12
10 Michael Hepburn (Aus) Mitchelton-Scott 00:01:23
2018 Tour de France General classification after stage 20
1 Geraint Thomas (GBr) Team Sky 80:30:37
2 Tom Dumoulin (Ned) Team Sunweb 00:01:51
3 Chris Froome (GBr) Team Sky 00:02:24
4 Primoz Roglic (Slo) LottoNL-Jumbo 00:03:22
5 Steven Kruijswijk (Ned) LottoNL-Jumbo 00:06:08
6 Romain Bardet (Fra) AG2R La Mondiale 00:06:57
7 Mikel Landa (Spa) Movistar Team 00:07:37
8 Daniel Martin (Irl) UAE Team Emirates 00:09:05
9 Ilnur Zakarin (Rus) Katusha-Alpecin 00:12:37
10 Nairo Quintana (Col) Movistar Team 00:14:18