Fenerbahce drew 0-0 at home against Benfica in the first leg of their qualifying playoff on Wednesday, despite the Portuguese team having a player sent off in the 71st minute.
In the north of Norway, Bodo/Glimt's fairytale rise in European soccer continued with a 5-0 rout of Sturm Graz in their playoff first leg.
Celtic failed to take home advantage in a 0-0 draw with Kairat Almaty, who host the return game four time zones from Scotland in Kazakhstan next Tuesday.
Basel captain Xherdan Shaqiri scored early with a penalty but the Swiss champions were held 1-1 at home by Copenhagen.
Seven playoffs will be decided with return games on Tuesday and Wednesday next week with the winners completing the 36-team Champions League lineup. The second-leg games include unheralded Pafos of Cyprus holding a 2-1 lead at home against Red Star Belgrade.
The Champions League draw ceremony to find out each team's eight opponents in the single-standings league format will be made on August 28 in Monaco.
Fenerbahce have not played for 17 years in the main Champions League, that Mourinho won twice: with Inter Milan in 2010 and Porto in 2004.
Mourinho's team dominated the last 20 minutes of play in Istanbul after Benfica midfielder Florentino was sent off for being shown a second yellow card.
A video review confirmed an offside call after Fenerbahce forward Youssef En-Nesyri thought he had scored in the 81st.
