After several attempts, Hermoso finally broke the deadlock in the 39th minute to silence the home fans in giving the visitors a lead before half time.
After the restart, the hosts' led by Payne fought hard to get on level terms but 80th-minute substitute Oshoala profited from Noelia Ramos' goalkeeping error to seal the victory for Barcelona.
Oshoala netted her third league goal of the season seven minutes after replacing Hermoso for Barcelona. The 24-year-old has now scored three times in two outings against Sevilla.
On the other hand, Nigeria-born US international Payne lasted the full duration. The result means Barcelona remain at the top of the table with 10 points from four games, while Sevilla are now 11th with three points.
Barcelona will aim to maintain their winning form when they face Sporting de Huelva on October 12 while Sevilla will seek to bounce back from three defeats against at Logrono.