Roma secured a 4-0 win over Swiss side Servette and last season’s runners-up took six of six draws in Group G.
Romelu Lukaku scored the hosts’ first match and has scored in their last thirteen Europa League matches, a streak that stretches back nine years.
Andrea Belotti scored twice and Lorenzo Pellegrini also added his decision to the scoreboard in the second half as Jose Mourinho’s side kept up the pace with Slavia Prague at the top of the group.
Atalanta won two out of two in Group D with a 2-1 win at Sporting Lisbon.
Defenders Giorgio Scalvini and Matteo Ruggeri gave the team a two-goal lead in a dominant first half, but Sporting stepped up in the second half, with former Coventry striker Viktor Gyokeres halving the deficit from the penalty spot.
Former Tottenham winger Marcus Edwards missed a one-on-one and Geny Catamo scored for Sporting as Atalanta held on to take the win.
Villarreal opened their Europa League with a 1-0 home win over Rennes.
Alexander Sorloth gave the Spaniards the lead impressively, but the visitors looked set to take a point when they received a penalty in extra time.
However, Pepe Reina rejected Martín Terrier for the group to continue scoring in three points of Group F.
Ajax has not won in six matches in all competitions after drawing 1-1 against AEK Athens.
Bayer Leverkusen continued their strong start to the crusade with their eighth win in their last nine matches in all competitions with a 2-1 away win over Molde.
Slavia Prague clinched top spot in Group G after beating Sheriff Tiraspol 6-0.
In the Europa Conference League, Fiorentina, last season’s runners-up, drew in stoppage time to earn a point at home to Hungary’s Ferencvaros.
Barnabas Varge and Ibrahim Cisse believed they had earned trouble for the visitors, Antonin Barak and Jonathan Ikone came off the bench to save a result for the Italian side.
Fiorentina’s comeback ended Ferencvaros’ 10-match winning streak in all competitions and means they have two problems with the organisation’s leaders.
Gent moved to the top of Group B with a 2-0 home win over Maccabi Tel Aviv.
Tarik Tissoudali scored two goals for the Belgian team, which was the first team to eliminate its Israeli visitors this season.
KI Klaksvik were the first team from the Faroe Islands to earn a point at UEFA festival level with a 0-0 draw with Lille.
Kosovar side Ballkani achieved their first home win in a European organization match, beating 2-0 Croatian champions Dinamo Zagreb.
Nordsjaelland were the first team to score seven goals in a Europa Conference League match and earned a 7–1 home win over Bulgarian side Ludogorets.