They fought, they scrapped, they even led for a while. But Viadana, as against Saracens in their previous match, just could not find the killer touch to take them past Glasgow in the Heineken Cup on Saturday, the Scots winning 18-15 at the Stadoi Communale.
The game left Glasgow coach Sean Lineen with mixed emotions in the wake of a jittery display.
The coach blamed dodgy refereeing by Frenchman Jerome Garces and the wretched conditions for his side's failure to grab a precious bonus point in their quest to reach the quarter-finals for the first time.
Lineen admitted he was relieved to get the victory.
"They made it hard for us. We made it hard for us. The referee made it hard for us," said Lineen.
"Viadana were struggling in the contact phase but a weak referee let anything go.
"They were offside all the time, but we did not deal with that situation.
"I was to focus on the fact that we won - the first away success for Glasgow in 28 Heineken Cup games.
"There was no bonus point, but it had been lashing down all day and the ground was very soft.
"They way we have been playing, I'll take the win.
"We only scored two tries, but we also created both their scores."
Glasgow surged ahead with a superbly-worked try by breakaway forward Kelly Brown - only to be pegged back almost instantly.
Colin Gregor made the telling thrust into the Viadana danger zone and after he was hauled down, the alert Dan Parks launched a beautifully-weighted chip to the right flank.
Brown was lurking all on his own and after bouncing off the challenge of Kaine Robertson, he was left with a cruise to the line.
Parks followed up with a pinpoint conversion - but the joy of the Warriors lasted a matter of seconds.
From the restart by Howarth, Glasgow skipper Ally Kellock palmed back the ball in an uncontrolled manner.
And from the loose ball, the home brigade created the sequence which led to South African number eight Jaco Erasmus ploughing over.
Howarth made amends for his penalty bungle by slotting the goal from an awkward angle to tie up the scores.
And the Warriors suffered a further major setback four minutes before the interval - with Erasmus again emerging as the hitman.
Howarth's cross kick was gathered by Colin Shaw, but he slipped on the greasy surface as he prepared to hoof the ball clear.
He was engulfed by several Viadana markers and was forced to give away a penalty for holding on to the ball too long.
Erasmus caught the Glasgow defence on the hop with a quick tapped kick before bullocking his way to the target.
And the score was awarded by French referee Jerome Garces on the say-so of his video assistant.
Howarth was off-target with the conversion - and there was still enough time for Parks to steady the Warriors' nerves with a penalty.
It was Glasgow who were next on the score sheet with another penalty by Parks.
They were still toiling to find penetration in attack, however, and it was not until the start of the last quarter that they imposed their authority through a touchdown from Argentinean full-back Bernie Stortoni.
His effort set up a tension-packed finale.
Substitute Corrado Pilat - on for Howarth - narrowed the leeway to just three with a penalty five minutes from the end.
Tries: Erasmus 2
Tries: Brown, Stortoni
Pens: Parks 2
Viadana: 15 Stuart Moffat, 14 Kaine Robertson (capt), 13 Garry Law, 12 Matthew Harvey, 11 Hayden Pedersen, 10 Calvin Howarth, 9 Craig McGrath, 8 Jaco Erasmus, 7 Aldo Birchall, 6 Joshua Sole, 5 Quintin Geldenhuys, 4 Ockert Booyse, 3 Ignacio Rouyet, 2 Luigi Ferraro, 1 Miguel Alonso.
Replacements: 16 Andrea Moretti, 17 André De Bonis, 18 Cristian Bezzi, 19 Sam Harding, 20 Steven Bortolussi, 21 Corrado Pilat, 22 Hayden Reid.
Glasgow Warriors: 15 Bernardo Stortoni, 14 Colin Shaw, 13 Colin Gregor, 12 Daryl Gibson, 11 Thom Evans, 10 Dan Parks, 9 Sam Pinder, 8 Johnnie Beattie, 7 John Barclay, 6 Kelly Brown, 5 Alastair Kellock (c), 4 Opeta Palepoi, 3 Ed Kalman, 2 Dougie Hall, 1 Kevin Tkachuk.
Replacements: 16 Eric Milligan, 17 Justin Va'a, 18 Moray Low, 19 Dan Turner, 20 James Eddie, 21 Scott Barrow, 22 Hefin O'Hare.
Referee: Jérôme Garces (France)
Touch judges: Patrick Pechambert (France), Jacques Laplace (New Zealand)