La Course 2017: GB's Lizzie Deignan second as Annemiek van Vleuten wins first stage
Britain's Lizzie Deignan finished second as Dutch rider Annemiek van Vleuten won stage one of the two-day La Course by the Tour de France.
Orica-Scott's Van Vleuten, 34, attacked the lead group in the final 5km to take victory on the Col d'Izoard summit.
Boels-Doemans rider Deignan, 28, was 43 seconds behind, with Italy's Elisa Longo Borghini a further 40 seconds back in third.
The race ends on Saturday with a 22.5km 'chase' in Marseille.
The top riders will set off according to the time gaps established on the opening stage, with Van Vleuten first on to the course.
Van Vleuten returned to action last year following a horrific crash while leading the road race at the Rio 2016 Olympics.
Deignan rues domestique role
Deignan, the British road race champion and former world champion, started the 67km stage in support of American team-mate Megan Guarnier and did the majority of the riding on the front of the peloton.
She helped bring back lone attacker Linda Villumsen of New Zealand with 9km to go, before an elite group of 10 riders established themselves in the final 6km of the Alpine climb, which averages 7.3% in gradient.
However, Deignan broke free with Australia's Shara Gillow before trying in vain to chase down Van Vleuten, while Guarnier recovered to finish fourth.
"I messed up by being a domestique then a leader, so it's my own fault for not having confidence in myself," Deignan told ITV4.
"Megan put her hand up at the start of the day and said she could be leader.
"I wouldn't call myself a time triallist but perhaps this gives me a chance [for overall victory]."
Guarnier finished 45 seconds behind Deignan, who could choose to wait for her team-mate on Saturday's stage so they can work together to chase down Van Vleuten.
'I didn't used to be a climber' - Van Vleuten
Van Vleuten suffered severe concussion and three small fractures in her back when she crashed heavily in the Olympic road race last year.
She has been in impressive form this season, winning two stages of the Giro Rosa stage race and leading the women's World Tour standings.
"To finish here in front of so many people is amazing," she said.
"I didn't used to be a climber but after the Olympic Games I proved that I can do it, so have worked more on my climbing."
Stage one result:
1. Annemiek Van Vleuten (Orica-Scott) 2hrs 7mins 18secs
2. Lizzie Deignan (Boels Dolmans Cyclingteam) +43secs
3. Elisa Longo Borghini (Wiggle Highs) +1min 23secs
4. Megan Guarnier (Boels Dolmans Cyclingteam) +1min 28secs
5. Shara Gillow (FDJ Nouvelle-Aquitaine Futuroscope) +1min 33secs
6. Amanda Spratt (Orica-Scott) +1min 41secs
7. Lauren Stephens (Team Tibco - Silicon Valley Bank) +1min 51secs
8. Ana Christina Sanabria Sanchez (Servetto Giusta) 2mins 24secs
9. Katarzyna Niewiadoma (WM3 Procycling) 2mins 52secs
10. Hanna Nilson (BTC City Ljubljana) 3mins 04secs