(Adds detail, quotes) MONTPELLIER, France, Sept 18 (Reuters) - Arsenal quickly recovered from an early setback to ruin Montpellier's Champions League debut with a 2-1 victory in their opening Group B match on Tuesday. With all eyes on former Montpellier favourite Olivier Giroud, returning to his old club just months after firing them to the title, goals from Lukas Podolski and Gervinho cancelled out Younes Belhanda's early penalty to earn Arsenal the points as they began a 15th straight season in the Champions League. ... More...