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.
Montpellier battled desperately for an equaliser after the break but Arsenal survived to maintain their record of never having lost a European tie against French opposition in France.
"It was great to score again. I like these situations, it was a great pass by Olivier [Giroud] and I feel good in those moments," Podolski said.
"We played well in the first half but not so good in the second. But we got the three points and that is important. We know we can improve."
It had all started so well for Montpellier.
There were just nine minutes on the clock when Thomas Vermaelen was adjudged to have fouled Belhanda on the edge of the area and the Moroccan got up to chip his spot-kick past Arsenal keeper Vito Mannone.
The raucous crowd loved it, but they were silenced after 16 minutes when Giroud demonstrated just why Arsenal had sought his signature, supplying a neat flick for Podolski to beat home keeper Geoffrey Jourdren.
Two minutes later Arsenal struck again. Carl Jenkinson's low cross into the area was seized upon by Gervinho who guided the ball into the net from close range.
The double blow knocked the stuffing out of Montpellier as Arsenal settled into their possession game although Remi Cabella did force Mannone into one fingertip save before the break.
Arsenal were forced to show defensive resilience in the second half as Montpellier chased the equaliser.
ANXIOUS MOMENTS
There were some anxious moments for Wenger, watching from high in the stands as he begins a three-match European ban for his behaviour towards match officials after Arsenal's exit against Milan last season.
Cabella's fine lob come back off the woodwork while Belhanda found himself in front of goal with 10 minutes left but only managed to fire his shot straight at Mannone.
Apart from his assist, Giroud was fairly quiet against his old club and was substituted with 20 minutes remaining, leaving the field to a warm ovation from the home fans.
Arsenal's assistant manager Steve Bould, thrust into the limelight for the night, said the Gunners had rode their luck a little after the break.
"We deserved to be in front at halftime but we looked a bit tired after the break and dropped a little bit and to be fair they played very well," he told Sky Sports.
Bould will also be on duty at pitch-side next week when Arsenal, who have not lost on the opening day of the Champions League since 2003, host Olympiakos while Montpellier travel to Schalke 04 who opened their campaign with a 2-1 victory against the Greek side.
