Canada not only had to try to overcome 15 men on the pitch, they were also enveloped in an antipathetic blanket of sound, an atmosphere that, once the stadium hosts its official 72,000 capacity, will be one of the most intimidating in world sport.
But the Canadians could not, and would not, be deterred from their purpose, which was to find out just how good they are as they prepare to participate in the first professional World Cup. From the feisty pre-kick-off huddle to the final surge down the right wing they showed they are prepared to slug it out with the best.
Their captain, Gareth Rees, admitted: "For me there were huge question marks over the developments in our game over the last three or four years. When we came here in 1993 we believed we could do something. But before this match I seriously wondered whether Canada could still compete now the game is professional.
"We have to be realistic about these things. These guys over here in Wales play the game for a living. They are involved in it day in, day out."
The question was probably not answered wholly to the Canada captain's satisfaction, but Rees, added: "That's the first time in a while we have put ourselves on the big stage against a so-called bigger nation and I was very happy with parts of the performance."
And if club commitments work against them when it comes to setting up squad sessions, there was little sign of weakness in Cardiff where they managed to rattle Wales and had the crowd upset even before the kick-off.
When the time came for the national anthems Rees drew his men around him, some way apart from the main body of celebrants, and they prepared to sing Oh Canada in a huddle.
The crowd howled and jeered its disapproval, but attempts by worried officials failed to loosen the bonding of the team, although they were persuaded to move closer to the halfway line.
Rees explained: "It was not intended to cause offence and we lined up and showed respect for the Welsh national anthem when that was sung. But we wanted to look each other in the face and hear each other when we were singing our anthem. We have done this for the last 15 tests."
According to Rees, when Clive Norling, the former international referee, scurried up to break up the huddle, he told them if they did not then there would be an incident.
There wasn't. Although, had Wales lost, as they did by two points back in 1993, it might have been different. Credit for that can be laid chiefly at the feet of fly-half Neil Jenkins.
It was his second half try which finally helped stitch an otherwise ragged Wales side together. That and the seven penalties and conversion of wing Nick Walne's first try for his country helped scour off the rust that had gathered since their stupendous victory over South Africa two months ago.
The Canadian defence had begun to look impregnable, and their back row threatening - Al Charron, winning his 50th cap, and Dan Baugh, who plays for Cardiff, were outstanding - whenever they went forward.
All Canada lacked was discipline and some cut to go with the thrust of the halfback pairing of Rees and Morgan Williams. Dave Lougheed, more familiarly a wing with Leicester, adapted well to a new role at outside centre, but inside him Scott Bryan did not make fire, while outside him the wings lacked a sense of direction at times, and just plain sense at others.
Wales captain Robert Howley, while not totally despondent - after all he became the first to lead his country in seven successive wins, surpassing Phil Bennett and Mervyn Davies with six apiece in the 1970s - did admit: "It was disappointing, especially early on, although I thought we got better."
But there were still too many unforced errors, too much spilled ball, and, at the start anyway, a lack of cohesion. Graham Henry, the coach was characteristically blunt. "We didn't play as well as we had hoped to play. But it was our first game for two months and we are feeling positive about facing France next weekend." Canada should be feeling similarly about their forthcoming confrontation with England at Twickenham on the same day.
Wales: Tries Jenkins, Walne; Conversion Jenkins ; Penalties Jenkins 7. Canada: Try Lougheed; Conversion Rees ; Penalties Rees 3; Drop Goal Rees.
Wales: S Howarth (Newport); N Walne, L Davies (both Cardiff), S Gibbs (Swansea), A Bateman (Northampton); N Jenkins, R Howley (both Cardiff, capt); P Rogers (Newport), J Humphreys (Cardiff), B Evans (Swansea), C Quinnell (Cardiff), A Moore (Swansea), G Lewis (Pontypridd), S Quinnell (Llanelli), M Williams (Cardiff). Replacements: A Lewis (Cardiff) for Humphreys, 45; G Llewellyn (Harlequins) for C Quinnell, 68; D Young (Cardiff) for Evans , 68; S Jones (Llanelli) for Gibbs, 80; C Wyatt (Llanelli) for S Quinnell, 80.
Canada: S Stewart (Bedford); W Stanley (James Bay), D Lougheed (Leicester), S Bryan (Balmy Beach) C Smith (Meraloma); G Rees (Bedford capt), M Williams (Pacific Pride); R Snow (Newport), M Cardinal (James Bay), R Bice (Vancouver Rowing Club), J Tait (Cardiff), M James (Perpignan), J Hutchinson (Suntory), A Charron (Bristol), D Baugh (Cardiff). Replacements: R Banks (Bedford) for Hutchinson, h-t; J Thiel (James Bay) for Bice, 69; M Schmid (Rotherham) for Tait, 69; B Ross (James Bay) for Rees, 75.
Referee: D McHugh (Ireland).