Glasgow’s scrum cornerstone Cusack could not be mistaken for anything other than a tighthead – he is an old-fashioned shape of prop rather than the new-look athletes – but the powerful front rower earned a stream of penalties from the forward exchanges which made victory comfortable.
Horne applied the finishing touches, Stuart Hogg came on and applied a little stardust, but this victory was built on the scrum power which brought the penalties and free kicks that gave Glasgow field position on which to build their game.
There will be tougher tests ahead with the Heineken Cup starting and a visit to Northampton next up, but it was encouraging for Glasgow to know that they are in good shape up front so they need not fear those challenges.
Glasgow were looking to maintain their 100 per cent record in Wales this season at a ground where Edinburgh had already won last month.
If they had every reason to be confident going into the game then they had many more reasons for that confidence as the match progressed.
Cardiff have struggled in the scrum all season and Cusack was the man to exploit those problems as he gave Campese Ma’afu a torrid time.
First he earned a stream of penalties as the Blues loosehead collapsed a series of scrums, then to try to get himself out of trouble the home player was looking to engage the hit as early as possible – too early, as he conceded a stream of free kicks.
That meant Glasgow usually found it easy to relieve the pressure and it was no surprise when Ma’afu did not come out for the second half.
For the second week it was Peter Horne who took over the goal kicking duties from Ruaridh Jackson.
His first effort, for offside, would have been described by Bill MacLaren as a “drunken” effort as it scraped over the bar thanks to a right-to-left draw.
His second penalty came from a turnover in the Glasgow half and an opportunistic kick ahead by flanker Johnny Barclay, this time it was a sweetly struck left-to-right shape as it sailed between the posts. The only thing in common between the two kicks was that they both went over, not a bad habit to have.
A ruck offence gave him a straightforward kick in front of the posts, before a collapsed scrum brought him the chance to make it four from four from roughly the spot of his first two.
Although Glasgow were going ahead through goalkicking, they were playing a game with the ball in hand which kept the pressure on the home side to earn the penalty chances.
Wales full-back Leigh Halfpenny did give the Blues some much-needed respite with a penalty just before half time, but it had been very much Glasgow’s half.
For those who were missing the X Factor on telly, Glasgow brought on their own X Factor player Hogg just before the break. He replaced Peter Murchie, who took a knock in his 50th game for the club, and it was Hogg’s second appearance of the season.
He showed that special class with a break from the back early in the second half to set up another penalty shot for Horne. It was wide out on the left but that made no odds as he was comfortably into his kicking stride by this point.
The change of Blues loosehead, with Taufa’ao Filise coming on, made little difference as another scrum penalty, this time for going up in the front row, gave Horne a simple chance to extend the lead
Cardiff started going for the corner or taking quick taps when they did earn penalties and Filise was able to show the other side to his game by bursting powerfully up the middle.
That created space out wide which saw Halfpenny going for the corner, only to have the ball knocked out of his hands by Hogg coming across.
Glasgow suffered some nervousness going into the final minutes when Dougie Hall was sent to the sin bin for a ruck offence that was deemed cynical, but the scrum continued to get the visitors out of trouble as Cusack came back on to the pitch for the injured Ryan Grant. Horne missed his first penalty of the night with what should have been a straightforward effort, but by then it did not matter and the visitors were able to see out the closing minutes for a comfortable victory.