The French club were held 20-20 at Calvisano in the opening round but centre Thomas Laranjeira scored 18 points, including one of his team's two tries, to finally clip the Falcons' wings.
However tries by Scott Lawson and Ryan Shortland ensured Newcastle at least departed south-west France with a losing bonus point that keeps them well in contention for top spot.
Newcastle are second in the pool though only courtesy of their late victory in the opening round over Bucharest Wolves, who claimed a 37-15 success against Calvisano.
Florin Vlaicu instigated the Wolves' recovery from the heartache of that narrow loss to Newcastle with 27 points that included six penalties, two conversions and one of his team's three tries.
However head coach Lynn Howells will rue not clinching a bonus point that would have taken his team top of the group ahead of their home and away fixtures against Brive.
Calvisano may have lost but are by no means out given the failure of the other sides to take maximum points in any of the pool games so far and will provide tricky opposition for Dean Richards' Newcastle in the coming rounds.