The fly-half, who is eyeing up the England No10 shirt for the 2013 Six Nations after making his debut in the famous victory over World Cup winners New Zealand last time out, kicked 17 points in the 47-3 victory.
But wing Monahan stole the show with four tries, with Rob Cook and Dan Robson also getting in on the act against a sorry Exiles side, who only managed a sole Tom Homer penalty in reply.
Another man putting his hand up for England involvement during the Six Nations is Tom Biggs, the wing helping himself to a try as Bath left Calvisano 39-5 victors.
Biggs was joined on the scoresheet by Simon Taylor, Jack Cuthbert, Mark McMillan and Horacio Agulla – the Argentine international grabbing a hat-trick.
Elsewhere Wales utility back James Hook seemingly put his hand up for the vacant fly-half jersey for the 2013 Six Nations by starring as Perpignan inflicted a first Challenge Cup defeat on Worcester, 13-6.
Hook will be one of the names, alongside Dan Biggar, mentioned to replace the injured Scarlets fly-half Rhys Priestland for Wales’ Six Nations defence, and he contributed eight crucial points to Perpignan’s victory.
Meanwhile, Grenoble got the better of London Welsh 27-13 while Bizkaia Gernika won away at Rovigo 16-10.
MORE: The latest football news
MORE: The latest tennis news