London: Arsenal, VfB Stuttgart and Olympiakos Piraeus all scored 2-0 away wins in their final Champions League playoff matches to take a big stride towards the group stage before next week`s second legs.
Arsenal became the first English club to win a European tie at Celtic since Nottingham Forest in 1983 with a deflected William Gallas effort and an own goal from Gary Caldwell giving them victory.
Stuttgart won at Politechnica Timisoara in Romania with two goals in three minutes from Timo Gebhart, who scored with a penalty, and former Arsenal midfielder Aleksandr Hleb.
Goalkeeper Jens Lehmann, who played for Arsenal before joining Stuttgart, announced before the match that he was retiring at the end of the season.
Olympiakos also scored a good away win and dented Sheriff Tiraspol`s hopes of becoming the first Moldovan team to qualify for the group stages with Dudu and substitute Kostas Mitroglou on target to give the Greek double winners their 2-0 victory.
In the two other matches, FC Copenhagen beat APOEL Nicosia 1-0 with a 51st-minute goal from Zdenek Pospech while Portugal`s Sporting had their first goalscorer, Montenegro striker Simon Vukcevic, sent off for celebrating his strike during their 2-2 home draw with Fiorentina.
He earned a second yellow card for taking his shirt off after scoring Sporting`s 58th-minute equaliser and now misses next week`s evenly-balanced second leg in Italy.
Juan Manuel Vargas put Fiorentina ahead after six minutes and after Vukcevic equalised, Miguel Veloso put Sporting 2-1 up with a thunderous 25-metre shot before Alberto Gilardino equalised for the visitors 11 minutes from time.