Quinn was forced to watch on aghast at Stamford Bridge as Sunderland slumped to a 7- 2 defeat at the hands of Chelsea.
The result, which was the club's worst since a similarly horrific 7-1 defeat at Everton in November 2007, extended the club's winless run to eight Premier League matches, and dispelled the last of the feelgood factor that had accompanied Bruce's arrival at the start of the season.
The former Wigan Athletic boss has struggled to arrest a slump that started more than a month-and-a-half ago, but having appointed him as Ricky Sbragia's successor in the summer, Quinn insists that Bruce remains the right man to turn Sunderland's fortunes around.
A day like (Saturday) hurts, said the chairman, who adhered to a long-standing agreement to appear on Sky Television's Goals on Sunday programme yesterday despite the weekend's humiliation.
But it's also a true test. I know one thing Steve is the perfect man for our club, and I mean that.
I'm not here to pat him on the back, and I'm saying that the day after a horrific result.
We've got a manager who knows what the club is about, who is from the region and knows it's different, who knows what it takes.
He hasn't had the best of luck with injuries and suspensions, and he's not got the thing rolling the way he wants in the last few weeks, everybody knows that.
But I also know it's possible and that it's there again.
My role as chairman is to support that.
Quinn has pledged to do all he can to aid Bruce's efforts to add to his squad during the current transfer window, and both parties are hopeful that defender Guy Demel will complete a £2m transfer from Hamburg this week.
Demel, who is currently representing Ivory Coast at the African Cup of Nations, is close to agreeing the terms of a move to the North-East after Sunderland were given permission to speak to his agent.
However, before a move is completed, the Black Cats will insist on the full-back completing a medical in Angola.
Sunderland are also closing in on Wigan left-back Maynor Figueroa, a long-term transfer target, but Bruce has ruled out any interest in Liverpool winger Ryan Babel, who was the subject of weekend rumours centred around a possible swap deal with Kenwyne Jones.
I keep hearing that, but where it's coming from I do not know, said Bruce.
The one thing I'm trying to do is build a squad to improve, so the last thing I want to do is trade or anything like that.
I don't know where that's come from, but it's simply not true.
Quinn expressed similar sentiments, and hinted that Jones would not be sold this month no matter what the likes of Stoke, Birmingham or Aston Villa offer.
Kenwyne knows exactly what I think about him, he said. I like him as a footballer.
He probably has five or six things in his locker that I never had. If things start to work out for him in the second half of the season, he can be a very important player for this football club.
Behind the scenes, agents might be trying to set up things for other football clubs, we can't do anything about that. But we don't want to get rid of anybody from the football club this month. If there's someone to sign in the other direction, we will do everything we can to help Steve.
Despite Saturday's setback, Quinn claimed that Sunderland remain on course to finish in the top half of the table.
There were a lot of mitigating circumstances, he explained.
We had a young team with seven or eight top players out. But I'm confident we're going to come back from this.
We have a big (FA Cup) game against Portsmouth coming up next weekend and I'm still confident we'll finish in the top half of the league and hopefully have a good cup run.