After seven years watching enviously from the sidelines, Arsenal have relished their return to Europe's Champions League.
The Gunners thrashed PSV Eindhoven 4-0 on Wednesday, brushing aside a team that were on a 26-game unbeaten run and had won eight and drawn one of their nine matches this season.
"You saw the motivation, the energy straight from the start," Arsenal's Martin Odegaard said.
"To be back in this competition is huge for us. You saw that on the pitch today."
England's other representative in Wednesday's action had a less happy evening.
Manchester United lost 4-3 at Bayern Munich but, after an error by goalkeeper Andre Onana gifted Bayern the lead, the tie was more one-sided than the scoreline suggests.
England captain Harry Kane scored on his Champions League debut for the German champions.
"I'm disappointed because we should stay in the game," United boss Erik ten Hag said.
"If you score three goals at Bayern Munich, you have to take a point."
Another Englishman, Jude Bellingham, struck in injury-time to earn Real Madrid a late win over Union Berlin, who were taking their bow in their competition.
It was Bellingham's sixth goal in as many games since joining Madrid.
"I'm a confident lad but I really couldn't have hoped for things to start as well as this in terms of goals," the 20-year-old attacking midfielder said.
"I hope I keep on scoring goals in minute 94 or 95 - although it might do my heart, and the club, good to score earlier."
RB Salzburg won 2-0 at at Benfica, while an own goal handed Napoli a late victory at Braga.
Galatasaray-Copenhagen, Real Sociedad-Inter Milan and Sevilla-Lens all ended in draws.
Arsenal's last Champions League tie was a 10-2 aggregate defeat to Bayern in December 2016. It has been a long wait to get back into Europe's premier competition and they did not waste any time.
Bukayo Saka scored after eight minutes, and Leonardo Trossard and Gabriel Jesus had them 3-0 up before the break.
Odegaard added a second-half fourth, sealing the perfect warm-up for this weekend's London derby against Ange Postecoglou's Tottenham.
"This was not a shock for us, we knew what to expect," PSV defender Jordan Teze said.
"Arsenal are a really good team, they have a lot of quality and play in a very smart way. We don't come up against teams like that in the Dutch competition."
Manchester United began brightly in Bavaria before Onana allowed a tame Leroy Sane shot to squirm under him in the 28th minute and Serge Gnabry added a quick second for the hosts.
Rasmus Hojlund pulled a goal back for United early in the second period before Kane, from the penalty spot after a harsh handball decision, restored Bayern's two-goal advantage.
In a frantic finish, Casemiro scored twice either side of a 92nd-minute strike from Bayern's Mathys Tel.
In the most eventful of the other ties, Turkish champions Galatasaray rallied from two down to draw 2-2 against 10-man Copenhagen.
- with AP
