For a team supposed to be scared of the ''cauldron'' of Parkhead, Arsenal did well to hide their fear as they gave themselves a great chance of progressing to the group stages by netting two away goals against Celtic.
Arsenal became the first English club to win a European tie at Celtic since Nottingham Forest in 1983 and it was the perfect result for Arsene Wenger, who kept the same side that dismantled Everton at the weekend. The Arsenal boss may now point to his team's recent successes as a reason not to invest further before the transfer window shuts at the end of the month.
Indeed, the criticism was levelled at Wenger that his side lacked a "spine" before the season began. With two high-profile departures in Kolo Toure and Emmanuel Adebayor, it was not difficult to predict a struggling start to the campaign for the Gunners, but the Frenchman will have been pleasantly surprised by a number of players who have stood up to fill the voids.
All eyes have been on how new signing Thomas Vermaelen settled into the side and the Belgian centre-back has been in fine form to cement his place in the first team. Strong and quick, Vermaelen's pace helped the Gunners out of a few sticky situations against Tony Mowbray's men - most notably when he charged back to thwart Scott Brown's effort on goal when all had looked lost.
The 23-year-old looks to have all the attributes of a top class defender, and Wenger has admitted his own surprise at how quickly the defender has adapted to the English game. It helps that veteran Frenchman William Gallas is also in ''the form of his life'' alongside him, but it is not only the Gunners' defence that is playing out of their skin.
Alex Song, in particular, has impressed at the heart of a midfield that has struggled to cope with the physical side of the game in recent years. The Cameroon midfielder showed at the African Cup of Nations that he has the potential to play as an imposing shield in front of the back four, but he has been unable to make the same mark on the Premier League thus far.
Until now. A dominating display against Everton was backed up by an incredible performance against Celtic - a side which will always test out the physical attributes of a player. Song was everywhere at Parkhead and his continual breaking up of possession, while also avoiding making a foul, made it easy for the Arsenal attack to function.
While the established forces of Robin van Persie and Andrei Arshavin may not be hitting the heights of what they are capable of, Wenger has been boosted by the displays of his lesser-known stars. Further tests await but, without taking anything for granted, one feels that the Gunners have enough to take back to the Emirates in order to secure that most lucrative of spots in the Champions League group stage.
They should be joined by VfB Stuttgart and Olympiakos, who also picked up 2-0 away wins in their qualifying games.
Ex-Arsenal midfielder Aleksandr Hleb may have ''regretted'' his decision to leave the club for a switch to Barcelona last year, but it appears the merits of having a happy player cannot be understated as he scored a wonder goal on his return to former club Stuttgart.
Hleb beat six players before curling a shot into the bottom corner from a tight angle and with the likes of Pavel Pogrebnyak, Ciprian Marica and Thomas Hitzlsperger in fine form, the German side could be dark horses if they progress to the next stage.
Romanian side Politechnica Timisoara may not have put up the hardest fight, but the on-loan Belarusian has always had the potential to score goals from midfield and may benefit from his decision to seek regular first-team football in Germany. Boasting incredible dribbling and passing skills, Hleb was initially viewed as the Gunners' replacement for Robert Pires when he joined the club in 2005 - but it is only upon his exit that fans may see the best of him.
Another former Arsenal player currently plying his trade at Stuttgart is German 'keeper Jens Lehmann and he took the opportunity to announce before the game that he would be hanging up his gloves at the end of this season.
Lehmann has never been a fans' favourite at any of his clubs because of his spiky persona and on-pitch histrionics, but will be a big loss to the game - not least because of his interesting views on fellow players, managers and referees. A job in the media may beckon.
Elsewhere, Olympiakos have been busy during this transfer market, but it was an acquisition from 2008 who helped them to a win over Sheriff Tiraspol in Moldova. Brazilian midfielder Dudu hit a contender for goal of the season with a blistering strike early in the second half, before Kostas Mitroglou scored on his Champions League debut to give the Greeks a decent advantage to take back home.
The news was not so good for Italian teams though, as legend Cesare Maldini claimed his country will struggle to win the Champions League with the players on show. "We need to wait until the end of the transfer market," he said. "Maybe Juventus and Milan will sign other players and the winning chances will change."
Fiorentina managed to snatch two away goals at Sporting Lisbon, but the result could have been very different if Sporting striker Simon Vukcevic had not been sent off in the 59th minute for taking his shirt off while celebrating a goal and, although the momentum may be with them, there are many things to fix if La Viola are to proceed.