Rudiger Selig (Bora Argon 18) and Nikias Arndt (Giant-Alpecin) finished second and third respectively, recording the same time as Drucker, who claimed his first ever win in a Grand Tour.
"I suffered a lot on Aubisque and I kept believing that there could be a bunch sprint at some point," Drucker said. "It’s the greatest victory in my career and it’s great to have a grand tour victory to my name.
"I was not really lucky in the first sprint stages but today was perfect. There was a bit of good positioning but also luck, being at the right place at the right moment.
There was no change at the top in the general classification, with Nairo Quintana (Movistar) maintaining his 3min 37sec lead over Tour de France champion Chris Froome (Sky).
Esteban Chaves (Orica-BikeExchange) stays third at 20 seconds off Froome, with five stages remaining.
The remaining opportunities for Froome and Chaves to gain some ground on Quintana lie in the two remaining mountain stages on Wednesday and Saturday and Thursday's individual time trial.
"Last night, the whole team really deserved a glass of cava to celebrate, as we did really well, but we had to remain serene after all," Quintana said.
"It really was needed to rest up well and keep our feed on the ground for today's nerves and the tough, difficult days ahead in the final week of the race. Not only Froome will be a rival: there's also Contador, even if he's also trailing behind, he's one you must keep an eye on for the entire race.
"Also Chaves, the whole Orica block in fact. Nothing should be taken for granted. Heat really struck us all today in the Vuelta, and it's difficult to cope with it, but everything comes a bit easier when you're in the leader's jersey. I stand heat well, actually, I prefer it to cold, even if I do well in cold, rainy conditions."
How it happened
They were 164 riders at the start on a hot and windy day. Davide Villella (Cannondale-Drapac), Mario Costa (Lampre-Merida), Silvan Dillier (BMC), Sven Erik Bystrom (Katusha), Luis Angel Mate (Cofidis) and JulienMorice (Direct Energie) broke away after four kilometres.
Simon Yates, fifth overall in GC, and his Orica-BikeExchange team-mate Sam Bewley crashed 53km into the stage but both were quickly back on their bike.
The leading group had a 2min 42sec advantage over the peloton, mostly led by sprinters’s teams, at the foot of the only climb of the day, the third-category Alto Castillo de Morella which Mate crested first.
The gap never went beyond 3min 35sec. The peloton split 56km from the line but reformed three kilometres further after some work by Trek-Segafredo.
Dillier attacked with 17.5km left just ahead of the intermediate sprint and he was followed by Bystrom and Mate as the other three were swallowed by the Tinkoff-led peloton.
With 12km remaining all riders were together and Giant-Alpecin and Dimension Data took over at the front looking to set up the bunch sprint for NikiasArndt and Kristian Sbaragli. Daniele Bennatti (Tinkoff), however, jumped away with three kilometres left and he was caught less than 500 metres from the line.
Drucker was then the strongest, benefiting from the slipstream of GianniMeersman (Etixx-Quick Step) who started his effort a bit too soon.
"It was pretty hectic but I had Danilo Wyss to keep me out of trouble," Drucker said. "I was pacing myself a bit behind to be able to go from behind with some speed. It was actually perfect. Gianni (Meersman) went and I went into his slipstream."