Alpecin-Deceuninck sprinter Kaden Groves seemed well-placed to win a third stage but was passed on the final corner, finishing fifth.
French rider Soupe, of the TotalEnergies team, got his wheel over the line in a photo finish as Aular almost caught him, securing his biggest career win to date.
Groupama-FDJ's Lenny Martinez, the youngest Vuelta leader in history, retains the red jersey which reigning champion Remco Evenepoel was happy to lose on Thursday.
Jose Herrada of Cofidis – in the final race of his career – and Burgos-BH's Ander Okamika attacked to create an early breakaway on the flat 200.8 kilometres between Utiel and Oliva.
Veteran Welsh rider, Geraint Thomas, a former Tour de France champion was one of a trio of Ineos riders who crashed early on before later returning to the peloton.
It was a far calmer ride than Thursday's frantic exploits, which saw Jumbo-Visma add a potential third general classification candidate in Sepp Kuss, who won stage six, while Primoz Roglic and Jonas Vingegaard took over half a minute out of Evenepoel.
The bunch caught Herrada but Okamika made it into the final 42 kilometres before he was swallowed up.
Green jersey Groves won the intermediate sprint ahead of Marijn van den Berg and Vingegaard to increase his points lead, with the Danish back-to-back Tour de France winner happily snatching up two bonus seconds.
A crash brought down Vingegaard's teammate Kuss with around 10 kilometres to go but the American was quickly back on his bike.
Another collision brought down Ineos rider Thymen Arensman five kilometres later and he needed medical assistance, before Soupe powered to victory.
Saturday's stage is more challenging, with a category one and a category three climb on the 165 kilometre run from Denia to Xorret de Cati.
This is the 78th edition of the race, which ends in Madrid on September 17 after 21 stages and 3 153.8 kilometres.