It's the Slovakian champion's first win in one of the major tours after his stage win at the Tour de France back in 2013. Since then, Sagan has missed out on stage wins in two Tours and a Vuelta but finally brought one home on the 158.4km route to the finish in Malaga.
Sagan showed no signs of hurt after being taken down in a crash on Sunday's stage two, and was back to his classic style of heading into the sprint with no lead-out from his team, despite Tinkoff-Saxo working hard to pull back the break earlier in the day.
Degenkolb's Giant teammates were the most active on the front as the peloton reached the final couple of kilometres in the city centre, however the German missed out to Frenchman Bouhanni and Sagan after launching his sprint early.
The day's main break formed from the off, with Sylvain Chavanel (IAM Cycling), Maarten Tjallingii (LottoNL-Jumbo), Walter Pedraza (Team Colombia), Martin Velits (Etixx-Quick Step), Alexis Gougeard (AG2R - La Mondiale), Omar Fraile (Caja Rural - Seguros RGA) Natnael Berhane (MTN-Qhubeka) and Ilia Koshevoy (Lampre-Merida) extending a maximum gap of over four minutes.
Things began to tumble on the category one Del Léon climb, with the peloton slowly reeling the remaining riders in before making the catch with 14 km to go.
The GC teams then came to the fore as the pace seemed to clam temporarily before an inevitable sprint finish, with Team Sky guiding Chris Froome safely home as the peloton began to stretch out with the accelerated pace in the last 5km.
Get The Leadout Newsletter
The latest race content, interviews, features, reviews and expert buying guides, direct to your inbox!
Orica-GreenEdge were able to protect their rider and race leader Esteban Chaves, who will continue to wear the red jersey into Tuesday's stage.
The fourth stage of the 2015 Vuelta will see the peloton navigate a relatively flat 209.4km course from Estepona to Vejer de la Frontera, before a tricky climb coming shortly before the finish to throw a spanner in the works for any sprinters who might have hoped for another opportunity.
Esteban Chaves on stage three of the 2015 Vuelta (Watson)
(Image credit: Watson)
Vuelta a España stage three: Mijas to Málaga (158.4km)
1. Peter Sagan (Slo) Tinkoff-Saxo, in 4-06-46
2. Nacer Bouhanni (Fra) Cofidis
3. John Degenkolb (Ger) Giant-Alpecin
4. Jean-Pierre Drucke (Lux) BMC
5. Ariel Richeze (Arg) Lampre-Merida
6. Kristian Sbaragli (Ita) MTN-Qhubeka
7. Mitchell Docker (Aus) Orica-GreenEdge
8. Jasper Stuyven (Bel) Trek Factory Racing
9. Vicente Reynes (Esp) IAM Cycling
10. Tom Van Asbroeck (Bel) LottoNL-Jumbo, all same time
The peloton in action during Stage 3 of the 2015 Vuelta a Espana (Watson)
(Image credit: Watson)
Overall classification after stage three
1. Esteban Chaves (Col) Orica-Green-Edge, in 8-04-01
2. Tom Dumoulin (Ned) Giant-Alpecin at 5s
3. Nicolas Roche (Irl) Team Sky at 15s
4. Daniel Martin (Irl) Cannondale-Garmin at 24s
5. Joaquim Rodriguez (Esp) Katusha at 35s
6. Nairo Quintana (Col) Movistar 36s
7. Alejandro Valverde (Esp) Movistar at 38s
8. Chris Froome (GBr) Team Sky at 40s
9. Daniel Moreno (Esp) Katusha st
10. Fabio Aru (Ita) 47s
Thank you for reading 20 articles this month* Join now for unlimited access
Richard is digital editor of Cycling Weekly. Joining the team in 2013, Richard became editor of the website in 2014 and coordinates site content and strategy, leading the news team in coverage of the world's biggest races and working with the tech editor to deliver comprehensive buying guides, reviews, and the latest product news.
An occasional racer, Richard spends most of his time preparing for long-distance touring rides these days, or getting out to the Surrey Hills on the weekend on his Specialized Tarmac SL6 (with an obligatory pub stop of course).
