The Blues got off to a bright start with Sam Warburton touching down just after four minutes but Montpellier hit back with tries from Timoci Nagusa, Rassie Van Vuuren and Yoan Audrin.
The gutsy Blues replied through winger Alex Cuthbert but Scottish back row Johnnie Beattie sealed the victory and bonus point with his touchdown on 58 minutes.
The Blues made five changes to the side that crashed to a 35-24 defeat last week. Warburton returned from illness and Lewis Jones started at scrum-half, replacing the suspended Lloyd Williams. The Welsh region lost two more players before kick-off with both Lou Reed and Marc Breeze dropping out of the squad – Reed due to his father Robert’s death.
Martin Bustos Moyano responded scored his side’s first points to bring the hosts within two points. Rhys Patchell restored the Blues’ cushion but Montpellier began to take control of the encounter.
Nagusa touched down with Moyano slotting the conversion and the French outfit turned the screw on their rivals.
The Blues were put under the kosh and eventually the pressure told. Van Vuuren was the beneficiary, as he pivoted at the back of a ruck to twist out of Andries Pretorius’ tackle to score.
Bustos Moyano added the extras to establish a 17-8 lead, which they hung onto at the interval.
Montpellier launched into the Blues immediately from the re-start with Audrin pouncing despite the best intentions of Patchell and Josh Navidi.
Bustos Moyano added the extras to establish a 16-point lead but the Blues fought back. Jason Tovey came close to snatching a try from a superb chip and chase and soon after Cuthbert burst clear, the Wales wing fending off Santiago Fernandez and racing away in the 51st minute.
Beattie hit back with a fourth try for Montpellier, though, and Bustos Moyano converted before Patchell and Bustos Moyano exchanged further penalties to round off the scoring.
