Chris Froome (Team Sky) survived a technical final descent and an attack from defending Tour de France champion Vincenzo Nibali (Astana) to retain his overall race lead after stage 17 to Gap on Monday.
Spaniard Ruben Plaza (Lampre-Merida) won the stage ahead of Peter Sagan (Tinkoff-Saxo) in second and Jarlinson Pantano (IAM Cycling) in third.
Plaza had attacked from an escape group 20 minutes ahead of the peloton on the final climb of Col de Manse to take a solo victory.
Froome maintains his overall race lead ahead of Nairo Quintana (Movistar) by 3-10, with Tejay van Garderen in third at 3-32. Despite crashing on the final descent and losing time, Welshman Geraint Thomas (Sky) retains his sixth place overall going into Tuesday’s second and final rest day.
Points classification leader Sagan got himself into the escape group for the third consecutive day, continuing his mission of vacuuming up as many points as possible to secure the green jersey.
The day’s 23-rider escape group was formed from two separate groups, one of 11 and one of 12, which joined after Sagan had taken maximum points at the intermediate sprint point after 86.5km.
On the steady climb towards the first categorised ascent of the day, Col de Cabre, the large lead group stretched out its gap over the peloton to over 12 minutes.
Sagan accelerated away from the break on the descent of the Col de Cabre, perhaps as a test for the final descent. He was briefly joined by Andriy Grivko (Astana) at the bottom of the downhill run, but they were caught by the rest of the break.
Grand Tour veteran Adam Hansen (Lotto-Soudal) was the next to attack, jumping clear of the break with 45km to go and was joined by Marco Haller (Katusha) 10km later. The duo hit the base of the Col de Manse with a minute’s lead over the chasers, and the peloton at 20 minutes.
Sagan, Simon Geschke (Giant-Alpecin), Ruben Plaza (Lampre-Merida), Christophe Riblon (Ag2r) and Daniel Teklehaimanot (MTN-Qhubeka) caught and passed Hansen and Haller mid-way up the Col de Manse, with Plaza immediately attacking and going solo. Thomas De Gendt (Lotto-Soudal), Jarlinson Pantano (IAM Cycling), Luis Mate (Cofidis), Bob Jungels (Trek) and Thomas Voeckler (Europcar) then bridged over to the chase group to make nine.
Sagan followed every attack from the chase group, determined not to allow anyone else get away as Plaza crested the top of the Col de Manse ahead and maintained his gap to take the victory despite a daredevil chase by Sagan. For the fifth time this Tour, Sagan had to settle for second place.
Behind, Roman Kreuziger led Tinkoff-Saxo team-mate Alberto Contador in front of Sky and Froome into the Col de Manse as the peloton was quickly whittled down to the overall contenders.
As widely predicted, Vincenzo Nibali (Astana) attacked on the descent of the Col de Manse, utilising his superior descending skills top open up a gap. Thomas was knocked off the road as Warren Barguil (Giant-Alpecin) went wide on a corner and nudged him sideways into a telegraph pole and down a bank. Thomas was helped back up by a spectator, remounted and finished the stage just 38 seconds down on Froome.
Nibali gained 28 seconds on his rivals after his downhill move, maintaining his eighth place and is now 7-49 behind Froome.
British national champion Peter Kennaugh (Team Sky) withdrew during the stage after suffering with illness for the past two days, leaving Sky with seven men to support Froome. Stage 13 winner Greg Van Avermaet (BMC Racing) was a non-starter, as he returned home to be with his pregnant wife.
The peloton will now have a chance to recuperate ahead of a tough final week in the Alps with the second rest day of the race on Tuesday. Racing resumes on Wednesday with stage 17, a climb-filled excursion from Digne-les-Bains over 161km that includes a final ascent to the finish line in Pra Loup.
Tour de France 2015, stage 16: Bourg-de-Péage to Gap, 201km
1. Ruben Plaza (Spa) Lampre-Merida in 4-30-10
2. Peter Sagan (Svk) Tinkoff-Saxo at 30 secs
3. Jarlinson Pantano (Col) IAM Cycling at 36 secs
4. Simon Geschke (Ger) Giant-Alpecin at 40 secs
5. Bob Jungels (Ned) Trek Factory Racing
6. Christophe Riblon (Fra) Ag2r at same time
7. Daniel Teklehaimanot (Eri) MTN-Qhubeka at 53 secs
8. Thomas De Gendt (Bel) Lotto-Soudal at 1-00
9. Luis Mate (Spa) Cofidis at 1-22
10. Thomas Voeckler (Fra) Europcar at same time
24. Vincenzo Nibali (Ita) Astana at 17-44
25. Alberto Contador (Spa) Tinkoff-Saxo at 18-12
28. Chris Froome (GBr) Team Sky at 18-12
30. Tejay van Garderen (USA) BMC Racing at 18-12
32. Nairo Quintana (Col) Movistar at 18-12
34. Geraint Thomas (GBr) Team Sky at 18-50
Overall classification after stage 16
1. Chris Froome (GBr) Team Sky in 64-47-16
2. Nairo Quintana (Col) Movistar at 3-10
3. Tejay van Garderen (USA) BMC Racing at 3-32
4. Alejandro Valverde (Spa) Movistar at 4-02
5. Alberto Contador (Spa) Tinkoff-Saxo at 4-23
6. Geraint Thomas (GBr) Team Sky at 5-32
7. Robert Gesink (Ned) LottoNL-Jumbo at 6-23
8. Vincenzo Nibali (Ita) Astana at 7-49
9. Bauke Mollema (Ned) Trek Factory Racing at 8-53
10. Warren Barguil (Fra) Giant-Alpecin at 11-03
Watch Cycling Weekly’s guide to the forthcoming Alpine stages