After suffering the ignominy of an early exit from the Champions League as defending champion, Chelsea began its quest to win the Europa League by beating Sparta Prague on Thursday.
Oscar scored late to give the London side a 1-0 victory - and a valuable away goal - in the first leg of the last-32 match.
His strike made up for another bad night for striker Fernando Torres, who has scored just one goal in 13 games.
"We have to create more opportunities and the strikers will score more goals," Chelsea manager Rafa Benitez said. "(Torres') work rate today was really good and thanks to him the rest of the team, especially the second line of offensive players, they could create."