Premier League leaders Chelsea made a winning start to their Group L campaign as Willian's seventh-minute effort was enough to see off PAOK at a hostile Toumba Stadium
Pierre-Emerick Aubameyang struck twice as Arsenal defeated Ukraine's Vorskla Poltava 4-2 in the Europa League on Thursday, while in-form Chelsea began their campaign with a 1-0 win away to PAOK in Greece.
Aubameyang has struggled to hit top gear in the Premier League so far with just one goal in five starts, but the Gabon striker opened the scoring in London after 32 minutes of the Group E encounter.
Danny Welbeck nodded in a second just after half-time and Aubameyang curled in the Gunners' third, with Mesut Ozil also on target before a lapse in concentration saw Vorskla hit back with two late goals.
"I think we played well in the first half and in the beginning of the second as well," Aubameyang told BT Sport.
"We have to improve and try to fight not to concede a goal like we did in the last minute."
Premier League leaders Chelsea made a winning start to their Group L campaign as Willian's seventh-minute effort was enough to see off PAOK at a hostile Toumba Stadium.
Rüdiger bypasses the midfield with his pass forward which Morata plays back for Jorginho who one-times a pass into Barkley's stride and with one touch the Englishman is running at the PAOK back line before assisting Willian whose shot gets under the advancing keeper. 0-1. #CFC pic.twitter.com/chwPdq48Ez— Chelsea GIFs (@ChelseaGIFs) September 20, 2018
Eden Hazard was omitted from the Chelsea squad at his own request due to fatigue, but manager Maurizio Sarri fielded a strong side as the Blues extended their winning run to six games in all competitions.
"We were in control of the match for 90 minutes. We had a lot of opportunities. We missed them and so I'm very happy with the three points, very happy with the performance, but not very happy with the result," said Sarri.
"When it's time to kill the match, we have to kill the match."
Steven Gerrard's Rangers acquitted themselves well on their first appearance in the group stage of a European competition since the 2010-11 Champions League, as they came away with a 2-2 draw against Villarreal.
A disastrous start for the Glasgow side saw Carlos Bacca fire Villarreal ahead inside 60 seconds, but Scott Arfield turned home a cross from Daniel Candeias to level on 67 minutes.
Gerard Moreno put the hosts back in front almost immediately, only for Kyle Lafferty to again hit back for Rangers as Gerrard's men made a solid start in Group G.
Leigh Griffiths hit a late winner for Celtic in a 1-0 home victory over Rosenborg, a team Brendan Rodgers' side knocked out in this season's Champions League qualifying rounds.
Salzburg triumphed in the clash of Red Bulls in the other Group B fixture as Fredrik Gulbrandsen scored a minute from time to give the Austrian club a 3-2 victory over RB Leipzig.
Marseille, last season's runners-up, slumped to a 2-1 home defeat by Eintracht Frankfurt in Group H as Luka Jovic grabbed an 89th-minute winner for the reigning German Cup champions.
Lucas Ocampos opened the scoring early for Marseille, who were playing behind closed doors at the Stade Velodrome after numerous crowd incidents last season.
But Lucas Torro levelled on 52 minutes for Eintracht before Jovic's late strike won it.
Dudelange, the first Luxembourg team to play in the Europa League group stage, made seven-time European champions AC Milan work hard for a 1-0 win in Group F.
Luxembourg's Grand Duke Henri and Grand Duchess Maria Teresa were in the crowd as Dudelange, who have a dozen non-professional players in their squad, succumbed to a deflected second-half goal by Gonzalo Higuain.
Record five-time winners Sevilla launched their Group J campaign with a 5-1 rout of Standard Liege, as Ever Banega and Wissam Ben Yedder both netted twice for the Spaniards.
Ludogorets (BUL) 2 (Keseru 8, Marcelinho 31) Bayer Leverkusen (GER) 3 (Havertz 38, 69, Kiese Thelin 63)
AEK Larnaca (CYP) 0 FC Zurich (SUI) 1 (Kololli 61-pen)
Celtic (SCO) 1 (Griffiths 87) Rosenborg (NOR) 0
RB Leipzig (GER) 2 (Laimer 70, Poulsen 82) RB Salzburg (AUT) 3 (Dabour 20, Haidara 22, Gulbrandsen 89)
Slavia Prague (CZE) 1 (Zmrhal 35) Bordeaux (FRA) 0
FC Copenhagen (DEN) 1 (Sotiriou 63) Zenit Saint Petersburg (RUS) 1 (Mak 44)
Dinamo Zagreb (CRO) 4 (Sunjic 16, Hajrovic 27, 57, Olmo 60) Fenerbahce (TUR) 1 (Neustadter 47)
Spartak Trnava (SVK) 1 (Oravec 79) Anderlecht (BEL) 0
Arsenal (ENG) 4 (Aubameyang 32, 56, Welbeck 48, Ozil 74) Vorskla Poltava (UKR) 2 (Chesnakov 77, Sharpar 90+4)
Sporting (POR) 2 (Rafinha 54, Cabral 88) Qarabag (AZE) 0
Olympiakos (GRE) 0 Betis (ESP) 0
Dudelange (LUX) 0 AC Milan (ITA) 1 (Higuain 59)
Rapid Vienna (AUT) 2 (Timofeev 50-og, Murg 68) Spartak Moscow (RUS) 0
Villarreal (ESP) 2 (Bacca 1, Gerard 69) Rangers (SCO) 2 (Arfield 67, Lafferty 76)
Lazio (ITA) 2 (Luis Alberto 14, Immobile 84-pen) Apollon Limassol (CYP) 1 (Zelaya 87)
Marseille (FRA) 1 (Ocampos 3) Eintracht Frankfurt (GER) 2 (Torro 52, Jovic 89)
Genk (BEL) 2 (Trossard 37, Samatta 71) Malmo (SWE) 0
Besiktas (TUR) 3 (Babel 51, Santiago Roco 69, Lens 82) Sarpsborg (NOR) 1 (Zachariassen 90+4)
Akhisar (TUR) 0 Krasnodar (RUS) 1 (Claesson 26)
Sevilla (ESP) 5 (Banega 8, 74-pen, Vazquez 41, Ben Yedder 49, 70) Standard Liege (BEL) 1 (Djenepo 39)
Dynamo Kiev (UKR) 2 (Tsyhankov 11, Garmash 45+2) Astana (KAZ) 2 (Anicic 21, Murtazayev 90+5)
Rennes (FRA) 2 (Sarr 31, Ben Arfa 90+1-pen) Jablonec (CZE) 1 (Travnik 54)
Vidi (HUN) 0 BATE (BLR) 2 (Tuominen 27, Filipenko 85)
PAOK (GRE) 0 Chelsea (ENG) 1 (Willian 7)