Stage 13 was designed for a break and Nelson Oliveira saw his boldness rewarded when he outwitted his breakaway companions to win on his own in Tarazona, handing his team Lampre-Merida their first stage laurels in this edition. The 26-year-old Portuguese attacked in the descent of the last of three climbs on the day's menu, 27 km from the finish, to clinch his first major victory, with a minute lead over Julien Simon (Cofidis) and Nicolas Roche (Sky).
Italy's Fabio Aru (Astana) retained his overall leader's red jersey.
The start was given at 13:18 to 173 riders. Maarten Wynants (LottoNL-Jumbo), suffering from stomach problems, did not start.
Several attacks took place in the first hour of the race, often involving Sylvain Chavanel (IAM). The Frenchman was instrumental in starting the break of the day on the 3rd category Collado de Oseja, when he went with Oliveira and Yukiya Arashiro (Europcar), soon joined by Alessandro De Marchi (BMC), Mikael Cherel (AG2R-La Mondiale), Jerome Coppel (IAM Cycling), Ruben Plaza (Lampre-Merida) and Cameron Meyer (Orica-Greenedge).
At the back, Nairo Quintana (Movistar), who had been sick for a few days, struggled to stay with the pack.
In the big climb of the day, Alto de Beraton (1st cat.), the eight front riders were joined by 16 others: Sergio Henao (Sky), Nicolas Roche (Sky), Rinaldo Nocentini (aG2R-La Mondiale), David Arroyo (Caja Rural-Seguros RGA), Yohan Bagot (Cofidis), Julien Simon (Cofidis), Niki Terpstra (Etixx Quick-Step), Gianluca Brambilla (Quick Step), Kenny Eissonde (FDJ), Kévin Reza (FDJ), Valerio Conti (Lampre-Merida), Maxime Monfort (Lotto-Soudal), Jose Joaquin Rojas (Movistar), Stephen Cummings (MTN-Qhubeka), Romain Sicard (Europcar) and Pawel Poljanski (Tinkoff-Saxo). Ruben Plaza was first at the top of the first two climbs of the day.
Alto de Beraton was merciless to Mattia Cattaneo (Lampre-Merida) and Mitchell Docker (Orica-GreenEdge), who called it quits.
With 100 km to go, the lead of the 24 escapees settled at 2:30 over a pack led by Fabio Aru's Astana team-mates. Twenty kilometres further, the gap rose to four minutes. In the third and last ascent, Alto de Moncayo (3rd cat), as the gap has gone down to 3:30, Oliveira and Chavanel tried to part company with the front group. Then Poljanski went on his own and reached the top ahead of a scattered breakaway bunch.
Nelson Oliveira attacked again in the descent as the gap went over five minutes. A time trial specialist, the Portuguese increased his lead regularly to cross the line on his own with a minute's lead over his former companions, led by Julien Simon et Nicolas Roche. The peloton crossed the line 4:48 later, allowing Brambilla and Sicard to climb up the GC to 9th and 10th respectively, 2:51 behind Aru.
