Ebdon, who first rose to prominence by winning the event in 1993, dominated his Scottish opponent from start to finish and knocked in a succession of sizeable breaks.
McManus, successful in six of their previous nine meetings, managed to accumulate only 25 points in the opening four frames. Ebdon compiled breaks of 62, 79, 89 and 84 prior to the mid-session interval and added a run of 57 when the action restarted to complete a whitewash.
"What's he had for breakfast?" joked McManus. "Peter played as well as anyone's ever played against me. When someone pots every one like that and oozes confidence there's not an awful lot you can do about it. He was going for everything and they were all going in."
Ebdon, who once fired in four century breaks - still a record for a best- of-nine-frame match - against McManus in a 1993 European Open qualifier, was delighted with the display.
"I've been working really hard on my game lately and things are just starting to come together. I feel I'm on an upward learning curve again," he said.
Ebdon, who has not captured a title since the Thailand Masters in March 1997, added: "I feel I'm getting to the point where I'm close to starting achieving my career goals."
The former World No 3, currently seventh in the rankings, next plays the winner of last night's intriguing encounter between Hong Kong's Marco Fu and Ronnie O'Sullivan.
Morco Fu was entering alien territory in more ways than one. The highly- rated 20-year-old from Hong Kong, who had already negotiated four rounds in the first world ranking event of his first full season as a professional, had never played O'Sullivan.
"I'm really excited about the match. He's special," said Fu, who did not know quite what to expect on his debut in the last 16 of a major tournament.
Fu, winner of the World Amateur Championship in Zimbabwe and the World Junior title in Ireland last year, is not alone in finding enigmatic O'Sullivan a tough riddle to solve.
After beating Mark King 5-2 in the previous round, O'Sullivan declared that he "hated the game" and was only at Preston Guild Hall because he had to be.
Hardly the right attitude to lift the trophy, it would seem, but O'Sullivan made a series of equally disenchanted remarks about his form at the Regal Scottish Masters earlier this month and still won first prize.
Chris Small suffered no adverse reaction to Monday's surprise win over John Parrott as he reached the quarter-finals by beating Nottingham's Anthony Hamilton 5-2 yesterday.
"I've got a few personal things sorted out and my whole attitude is different this season to last," said Small, who complained his dismal results during the 1997-98 campaign were partly down to a split from the mother of his child.
"I used to be content with getting to the last 16 or the odd quarter- final, but now I think I can do something bigger and go further," the 25-year-old from Edinburgh declared.
From 2-2 Small, ranked No 25 in the world, gradually pulled away with thoughtful contributions of 62, 32, 37 and 45. He will now play Gary Wilkinson or fellow countryman Jamie Burnett.Reuse content