Arsenal come from behind to beat Cologne but Everton lost to Atalanta
Atalanta's first half charge saw them sweep past Premier League Everton and claim an emphatic 3-0 win in their Europa League Group E opener in Reggio Emilia.
The Serie A strugglers opened the scoring in the 27th minute against Ronald Koeman's men who were still reeling from their 3-0 loss to Tottenham five days earlier.
Andrea Masiello tapped home the opener from close range and Alejandro Gomez made it 2-0 in the 41st minute with a powerful drive into the top corner.
Three minutes later Bryan Cristante increased Atalanta's lead and the home side continued to press as they held onto their advantage with ease.
Also in Group E, Adrian Sardinero grabbed an equaliser deep into injury time as Apollon grabbed a 1-1 draw at home to Lyon, who led through a Memphis Depay penalty.
There was more good news for Italy in Group D where Andre Silva scored a hat-trick as Milan cruised to an emphatic 5-1 win away to Austria Vienna.
The Portugal star scored his first goal in the 10th minute shortly after Hakan Calhanoglu had already fired Vincenzo Montella's men in front.
Silva added his second after 20 minutes and despite Alexandar Borkovic briefly reducing the deficit, second half goals from Silva and Suso eased the Serie A side home.
AEK Athens also got their Group D campaign off to a winning start with a 2-1 success in Rijeka, goals from Petros Mantalos and Lazaros Christodoulopoulos sandwiching a Josip Elez strike.
There was a shock for Bundesliga Hoffenheim in Group C as they fell to a 2-1 defeat at home to Sporting Braga, Joao Carlos and Dyego Sousa scoring in the visitors' come from behind win after Sandro Wagner gave the hosts an early lead.
In the other game in Group C, Ludogorets held Istanbul Basaksehir to a goalless draw in the Turkish capital.
Meanwhile Group C Villarreal were forced to work to overcome Kazakhstan's Astana 3-1, two goals in the last 15 minutes from Cedric Bakambu and Denis Cheryshev seeing them home.
Nicola Sansone had put the La Liga side in front in the 16th minute only for Yuri Logvinenko to threaten an upset when he equalised in the 68th minute.
Slavia Prague joined Villarreal at the top of Group A after Tomas Necid's 12th minute strike was enough to see them past Maccabi Tel Aviv in the Czech capital.
In Group B, Sergey Sydorchuk, Junior Moraes and Dieumerci Mbokani saw Dinamo Kiev come from behind to claim a 3-1 win over Skenderbeu, who led through Gjergj Muzaka.
Meanwhile Young Boys and Partizan Belgrade battled out a 1-1 draw in Switzerland, Marko Jankovic's early goal for the visitors quickly cancelled out by Christian Fassnacht.
Both games in Group F finished goalless, Zlin and Sheriff drawing a blank in Olomouc and Copenhagen and Lokomotiv Moscow doing the same in Denmark.