The Belgian finished a hair’s breadth in front of sprinters Sagan and Viviani
Jelle Wallays from Lotto-Soudal denied the sprinters victory and won from a three-man breakaway on stage 18 of the Vuelta a España.
The Belgian went clear in the first three kilometres of the race alongside Sven Eryk Bytrom (UAE Team Emirates) and Jetse Bol (Burgos-BH) and held on for a nail-biting win.
Simon Yates (Mitchelton-Scott) held onto his lead, with no change in the overall standings.
How it happened
The peloton rolled out from Ejea de los Caballeros ready to race the 186km to Lledia near the Pyrenees.
Stage 18’s profile was geared for the sprinters, with not a single categorised climb on the course.
As the riders hit the kilometre zero marker, three riders immediately jumped clear and built up a lead of 11 seconds just three kilometres into the race.
The breakaway trio – Jelle Wallays (Lotto-Soudal), Sven Eryk Bytrom (UAE Team Emirates) and Jetse Bol (Burgos-BH) – pulled out a three-minute gap on the bunch.
Quick-Step Floors took the lead and were joined by Trek-Segafredo to control the peloton and keep the gap at three minutes.
By 70km into the race Quick-Step and Trek had reduced the gap down to 2-14, keeping the escapees on a tight leash to set up their respective sprinters Elia Viviani and Giacomo Nizzolo.
An uneventful next 100km followed, with the GC teams being gifted an easier day as the sprinters looked toward the finish.
The gap to the breakaway bounced between two and three minutes, but Quick-Step and Trek ensured the trio were kept well within range.
Then with around 20km left to ride, the gap began to tumble and the Wallays, Bytrom and Bol put the hammer down to stay away.
Bol cracked with 7km to go, leaving the Lotto-Soudal and UAE pairing to struggle on for the line.
As the duo came into the final 2km became clear that the peloton may have misjudged the effort, with the breakaway staying ahead.
Sagan was the first to break formation and sprint early to try and reach Wallays and Bytrom, who were watching each other on the run in.
Wallays then beat his UAE rival and held off the rapidly gaining sprinters to pick up the victory.
Friday’s stage marks a return to the GC battle, with a mostly uphill 157km slog leading to the first category Coll de la Rabassa.
The 17.5km climb average’s 6,3% gradient, with a maximum of almost 14% on the lower slopes.
Vuelta a España 2018, stage 18: Ejea de los Caballeros to Lleida (186km)
1. Jelle Wallays (Bel) Lotto-Soudal, in 3-57-03
2. Sven Erik Bystrøm (Nor) UAE Team Emirates
3. Peter Sagan (Svk) Bora-Hansgrohe
4. Elia Viviani (Ita) Quick-Step Floors
5. Ivan Garcia (Esp) Bahrain-Merida
6. Danny van Poppel (Ned) LottoNL-Jumbo
7. Jon Aberasturi Izaga (Esp) Euskadi Basque Country-Murias
8. Tom Van Asbroeck (Bel) EF Education First-Drapac
9. Giacomo Nizzolo (Ita) Trek-Segafredo
10. Ryan Gibbons (RSA) Dimension Data, all same time
Overall classification after stage 17
1. Simon Yates (Gbr) Mitchelton-Scott, in 73-02-37
2. Alejandro Valverde (Esp) Movistar Team, at 25s
3. Enric Mas (Esp) Quick-Step Floors, at 1-22
4. Miguel Angel Lopez (Col) Astana Pro Team, at 1-36
5. Steven Kruijswijk (Ned) LottoNL-Jumbo, at 1-48
6. Nairo Quintana (Col) Movistar Team, at 2-11
7. Ion Izagirre (Esp) Bahrain-Merida, at 4-09
8. Rigoberto Uran (Col) EF Education First-Drapac, at 4-36
9. Thibaut Pinot (Fra) Groupama-FDJ, at 5-31
10. Tony Gallopin (Fra) AG2R La Mondiale, at 6-05