Five tries and a flawless goal-kicking performance by Dan Parks saw Glasgow Warriors through last night but Sean Lineen was scathing about his side's performance.

"That was embarrassing and frustrating," said the head coach. "I've absolutely nothing good to say about that game other than that we got the five points. I don't want to blame any one individual. It was just a bad day at the office, but that's as underwhelming a performance as I've seen from a Glasgow side."

Even so, as well as maintaining their unbeaten home record this season, his men remain in the running for a Heineken Cup quarter-final place, largely thanks to Parks whose 21-point haul included a try.

James Jones, the Welsh ref-eree who put in a shocking performance when Munster visited Firhill last month, was by no means the main culprit this time. He did incur the wrath of the home support when adjudging what might have been a scoring pass by Parks to Hefin O'Hare to be forward early in the match, but it was a blunder by Bernie Stortoni that really set the tone.

The Argentine full-back had plenty time to field Calvin Howarth's Garryowen but seemed to lose it at the last moment and ducked away from the ball allowing it to bounce perfectly for Hayden Pedersen who jogged in for the score.

If that was a gift then the favour was returned soon after. It looked like O'Hare had wasted a scoring chance on the left in cutting infield away from his support before trying to deliver a pass which Kaine Robertson had covered. However the ball rebounded off the Italian international wing and into the path of the Warriors winger, putting him clear.

Parks converted to level then nudged his side ahead with a penalty before scoring their second try after 20 minutes. He had again opted to shift play left, where this time Graeme Morrison turned on the power in midfield to punch a hole in the defence before showing real awareness to realise there was space on the inside to put his stand-off through and Parks had sufficient pace to scamper over.

From the restart, Morrison was further rewarded for his efforts with a try of his own. Again there was an element of luck as Scott Barrow, his midfield partner, initially failed to gather a pass. As it bounced behind him, he regathered and spun to find himself through the defensive line and he made ground into the Viadana half before realising Morrison had the momentum and angle to get to the right corner.

Any sense the Warriors had that they could relax and wait for the bonus point to come was removed when the referee once again slipped up badly, allowing Viadana to score their second try. As he pursued a chip into the 22, Pedersen was very much second favourite until he blatantly shoved John Beattie in the back, but somehow that went unnoticed and the winger was allowed to chase on before appearing to knock the ball on as he collected it on the way to the line.

Howarth failed with a pen-alty attempt from halfway at the end of the half but from slightly closer knocked one over after the break to get his side within a score and that sent the jitters through the home side.

A frenetic series of slapped passes ended with Stortoni trapped under the posts and forced to concede a penalty at which his team-mates went to sleep, failing to regroup as Steven Bortollusi took it quickly, allowing Aldo Birchall to go over which, in turn, let Howarth level with the conversion.

After Parks regained the lead with a penalty, his side spurned a succession of chances, but the pressure was telling and Dion Waller was eventually sin-binned for killing the ball. That allowed the Warriors scrummage to get on top and a power-ful shove set up the chance for replacement scrum-half Sam Pinder to dart over and finally secure the bonus point.

The win still needed to be wrapped up and was when Stortoni broke down the left and found support from Pinder who could perhaps have got there but made sure by finding Johnny Barclay as ever in support and unstoppable when col- lecting at pace 15 metres out.

Viadana went home with a four-try bonus point of their own, however, when Borto-lussi chased his own chip down the left touchline and gathered to score, Howarth converting.