Leonardo Sarto scored against his former side as Glasgow Warriors battled to their fourth Guinness PRO12 victory of the season in a hard-fought 33-28 encounter against Zebre in Italy.

The Italian international dotted down soon after the restart following superb work by Nick Grigg, with the centre delivering a masterclass to play his part in three tries in the Warriors’ bonus-point success.

Sean Lamont was also on hand to score twice, but the 2014-15 Guinness PRO12 champions far from had the situation their own way against a side who had not beaten them in eight previous encounters in the competition.

But despite their wretched record, it was Zebre who started on the front foot, playing through the phases to eventually catch the visitors offside as Carlo Canna kicked for the early lead.

It wasn’t to last long, however, with Lee Jones haring down the wing, halted in his tracks to find Lamont on hand to dot down with less than ten minutes played.

Despite their lead, Glasgow will have considered themselves far from their fluent best with a number of penalties conceded, Canna making the most of the opportunity to put the hosts 6-5 to the good.

It made for a rather end-to-end encounter as Rory Clegg kicked twice from in front of the posts to restore a Warriors lead, but once again Zebre made the most of a kick-off, hooker Oliviero Fabiani eventually showing great footwork to manoeuvre his way over and level the game.

It seemed as if the game would be on terms by the break, but fantastic work from Grigg saw the centre run from 90 metres from his own 22. He was eventually tackled, but with the Italian defence regrouping, Fraser Brown touched down in the corner for a seven-point lead after a conversion.

It gave the Warriors a head of steam heading into the second half, momentum they made the most of, counter-attacking to good effect as Lamont scored his second of the afternoon, courtesy of another Grigg offload.

Despite a 14-point deficit, Zebre were far from out of the game, but it was a former player who came back to haunt them as Sarto raced down the left wing to score.

Grigg was once again the architect, profiting from a quick penalty to stretch the defence before Sarto mopped up against the side he enjoyed four Guinness PRO12 years until the summer, securing the bonus point in the process.

And the breathless second half showed no signs of letting up, with replacement Thomas Boni putting through a neat grubber for Venditti to collect and run home to make it 18-30 heading to the last quarter.

Rob Harley was sent to the sin bin for pulling down the line-out as Zebre kept pushing, but a strong Glasgow defence kept the difference at a vital 12 points as the clock ticked away for the Italians.

Their pressure eventually told though as Andries van Schalkwyk ran through, and with a successful conversion making it a five-point encounter, a frantic finish was in store.

However, Zebre were not able to get their first win of the Guinness PRO12 season, Clegg kicking the decisive penalty to seal a ninth successive win over their Italian counterparts for Glasgow.

Guinness PRO12 Final 2017 Ticket Information: Fans can save up to 20% on selected tickets, and prices start at just €30 adults and €5 child, and be booked via www.ticketmaster.ie. For further information visit http://www.pro12rugby.com/final