Catrakilis produced a flawless performance from the kicking tee, while Bismarck du Plessis was a force of nature at the breakdown, with Montpellier building their win on an accurate kicking display and ferocious physicality in the forward exchanges.
The opening quarter was an understandably cagey affair as both teams sought to settle into their stride, but a couple of early errors from Montpellier provided Harlequins with the opportunity to open the scoring with a fifth-minute penalty to flyhalf Nick Evans.
However, Montpellier gradually began to assert their physicality at the set pieces and breakdown, while Catrakilis was able to cash in on a penalty won at scrum time to draw the scores level.
With few clear-cut opportunities early on, something special was needed to crack open the defence, and it came from big South African lock Paul Willemse, who produced a barnstorming break from the halfway line. The ball was recycled and Frans Steyn sent out a beautiful long pass to create the space for Jesse Mogg to be put away for the first try of the night.
Catrakilis slotted another penalty soon after to edge Montpellier into a handy 10-point lead on the half-hour mark, but their discipline then let them down during the latter stages of the first half as Evans knocked over two more penalties to reduce the deficit to just four points at the break.
It threatened to signify a momentum shift, and the break undoubtedly came at a good time in order to enable Jake White to have a few words with his Montpellier charges, and they came out with real purpose in the second half.
