Italian clubs carried on where they left off last season as Inter Milan and Juventus made it a perfect start for Serie A in the Champions League on Wednesday.
Inter Milan crushed Arsenal 3-0 at Highbury while Juventus, last season's beaten European finalists, beat Galatasaray 2-1 in Turin to follow wins by European champions AC Milan (1-0 over Ajax Amsterdam) and Lazio (2-0 winners at Besiktas) on Tuesday.
After providing three semi-finalists last season and an all-Italian Champions League final, the renaissance has continued with all four Italian clubs winning over the two opening matchday nights of this season's competition.
Inter, beaten by Milan in the semi-final last season, stole Wednesday's honours with a deserved Group B victory at Arsenal as the first-ever European meeting between the two clubs ended in the London side's biggest home defeat for two-and-a-half years.
Arsenal have now failed to win in six successive home matches in the Champions League and coach Arsene Wenger could not hide his disappointment afterwards.
"We started brightly, but we were perhaps a little naive on the goals and made it difficult for ourselves. It's painful enough to lose, now we must stick together and respond well in the next (Champions League) game.
"We made it very hard for ourselves by going 3-0 down by halftime, but there are five games to go and we must play better in the next one in Moscow (against Lokomotiv)."
Inter's Dutch scorer Andy Van der Meyde said: "I'm still surprised we were 3-0 up at half-time, we expected a very hard match. It's a dream start for us and we can go home happy now."
A well-worked goal from Julio Ricardo Cruz (21), a stunning angled volley from Van der Meyde (24), which goal-keeper Jens Lehmann could only help parry into the net, and a cool finish by Nigerian youngster Obafemi Martins (41) sent Arsenal crashing to what could ultimately prove a very costly defeat.
To complete a miserable night for Arsenal, Inter 'keeper Francesco Toldo also saved a Thierry Henry penalty after 32 minutes.
While Inter, without injured striker Christian Vieri, were outstanding, Juventus gave a more workmanlike performance that in the end still proved too good for Galatasaray in front of just 14,000 fans at their Group D match in Turin.
A 73rd minute goal, claimed by defender Ciro Ferrara, gave Juve victory, although he only appeared to get the slightest touch to an Alessandro Del Piero free kick.
Del Piero had put Juventus ahead in the fifth minute, when he was given a surprising amount of space to hook home a right-wing cross from Mauro Camoranesi. But Juve struggled after Hakan Sukur brought Galatasaray level with a 19th minute header.
Del Piero, who had struck the bar with a 66th minute free kick, set up the winner with 36-year-old defender Ferrara left unattended to poke his cross past Faryd Mondragon.
Meanwhile, in a battle between two former European champions, Celtic, last season's UEFA Cup runners-up, threatened an upset at Bayern Munich in Group A after dominating much of the game against the German champions.
Alan Thompson headed Celtic ahead after 57 minutes but Bayern recovered to win 2-1 with two goals from new signing Roy Makaay in the last 17 minutes -- the winner a speculative long-range curler four minutes from time.
"I'm bitterly disappointed, we controlled 75 minutes of the game against one of the best sides in Europe and ended up with nothing," Celtic manager Martin O'Neill told Sky Sports.
But goalscorer Makaay, winner of last season's Golden Shoe after 32 goals for Deportivo Coruna, said: "We had a lot of chances in the second half. We knew Celtic would make problems for us and they did, but its important to start the Champions League with three points and we did just that."
Olympique Lyon beat Anderlecht 1-0 in the other match in the group with Juninho Pernambucano scoring the only goal from the penalty spot after 26 minutes.
Former Real Madrid striker Fernando Morientes marked his European debut for Monaco, where he is spending the season on loan, with the opening goal in a 2-1 win over PSV Eindhoven in their Group C match.
Morientes struck with a far post header after 31 minutes before Edouard Cisse added a second after a breakaway attack in the 56th minute.
Wilfred Bouma powered home a free-kick for PSV after 65 minutes, but Monaco held on for all three points.
AEK Athens and Deportivo Coruna drew 1-1 in the other Group C match with Vassilis Tsiartas equalising for AEK in the 89th minute after Walter Pandiani had put Depor ahead on 12 minutes.
A late penalty from striker Darko Kovacevic gave Real Sociedad a 1-0 win over Olympiakos in Group D, while substitute striker Diogo Rincon scored twice in the last seven minutes as Dynamo Kiev beat Lokomotiv Moscow 2-0 in Group B.