THE size of the scoreline may suggest this was a rout, but Glasgow only really imposed themselves on their Italian opponents after a half-time dressing-down by head coach Dave Rennie.

The sole objective from the game, really, was to get the bonus-point victory that would boost the Warriors’ PRO14 play-off prospects, and in the end they did twice as much as they needed in that respect, finishing up with eight tries.

But they lost their way for a long stretch in the first half, going behind after establishing an early 14-0 lead, and needed to reimpose themselves before eventually making their class tell.

“We took a bit of stick at half time for compounding errors that let them back into the game,” said man-of-the-match George Horne, who scored two of his team’s eight touchdowns. “It wasn’t easy kicking into that wind and we played up our own backsides a bit, but we got a bit of a speaking to at half time and did better in the second half.

“That was a massive win for us as we had let ourselves get a bit behind the top three in our Conference table and we know every game is a must-win one now.”

Glasgow certainly still have a fair bit of work to do in Conference A, where they lie fourth, two points behind Cheetahs, who have a game in hand. And against tougher opponents this sort of flawed display could prove costly, as it did on several occasions earlier in the season.

Rennie needed no reminding of his team’s tendency to go off the rails at times, and his well-chosen words at the interval ensured they got back on the straight and narrow for the second 40.

“We started the way we wanted, but then we got loose for 25 minutes, didn’t kick when it was on to kick – it was like we felt the breeze was too tough to kick into,” he said.

“We made a couple of errors and put ourselves under pressure and let in a couple of soft tries. We were frustrated at half time but we got the response we wanted. We played a bit of territory and were pretty clinical when we got opportunities.”

It was Horne who opened the scoring in the sixth minute off an assist by Nick Grigg, and it was not long before Matt Fagerson got the second try. But if those two scores suggested the whole game was going to become a turkey shoot, the Italians had other ideas.

Glasgow were playing too loose, especially deep in their own half, and eventually Zebre made them pay through loosehead prop Daniele Rimpeli. Michelangelo Biondelli then added a penalty to further encourage the Italians into believing they could pull off an upset.

With Leone Nakarawa orchestrating some of the attacks on his second home debut and props Aki Seiuli and Oli Kebble enjoying the fray in the open, Glasgow patently had superior power as well as greater inventiveness. But in the closing stages of the first half they allowed far too many mistakes to creep into their game, and went behind when full-back Junior Laloifi broke through the defensive line and put substitute Marcello Violi through for a second try. Violi converted his own score, and from 14-0 down Zebre were 17-14 up.

That, finally, was enough to awaken Glasgow from their slumbers, and barely 60 seconds later they were back in front, as a penalty to touch was mauled, then Horne finished off after George Turner was stopped short. Pete Horne added the two points to put the home side four points ahead at the break.

Playing with a strengthening wind at their backs in the second half, Glasgow laboured initially as they went in search of the bonus-point try. But eventually a magnificent off-load from Nakarawa produced the score for fellow-Fijian Mesu Dolokoto, who had come on for his debut just minutes earlier.

The tension eased, the Warriors took no time to extend their lead, with a Pete Horne cross-kick going straight to DTH van der Merwe. Pete Horne again converted, and a match that had looked nervy was in the bag at 35-17.

George Horne was then denied his hat-trick, but only by a penalty try as Laloifi was yellow-carded for high-tackling him into touch a couple of metres out.

With time running out Tom Gordon got try No. 7 for Glasgow, then Pierre Bruno thought he had claimed the last word for the visitors with his own team’s third, before Dolokoto rounded off the scoring with his second two minutes from time.

Scorers. Glasgow. Tries G Horne 2, Fagerson, Dolokoto 2, Van der Merwe, penalty try, Gordon. Cons: P Horne 5, Jackson 2.

Zebre. Tries Rimpelli, Violi, Bruno. Cons Biondelli, Violi 2. Pen

Biondelli.

Glasgow Warriors G Bryce; T Seymour, N Grigg, S McDowall, D van der Merwe (K Steyn 68); P Horne (R Jackson 68), G Horne (J Dobie 56); A Seiuli (A Allan 66), G Turner (M Dolokoto 43 temp rep), O Kebble (A Nicol 63), R Harley (T Swinson 59), L Nakarawa, R Wilson (captain), T Gordon, M Fagerson (C Fusaro 59).

Zebre J Laloifi; P Balekana, J Elliott, T Boni, P Bruno; M Biondelli (M Violi 32), J Renton; D Rimpelli (R Brugnara 55), M Ceciliani (O Fabiani 55), E Bello (A Tarus 55), I Nagle (G Biagi 52), M Kearney (L Krumov 66), M Mbanda, A Tauyavuca (J Tuivaiti 48), R Giammarioli.

Referee: J Neville (Ireland). Att: 6692.