Matthew, the world No5 from Sheffield who made history in 2006 by becoming the first home winner of the title for 67 years, breezed past fellow countryman Chris Simpson, a qualifier from Guernsey, 12-10, 11-2, 11-5.
"We've got a good bunch of up-and-coming players pushing us hard - and Chris is one of them. Every single rally I had to push hard - all credit to him," said the fourth seed who now meets Australian Cameron Pilley.
Daryl Selby claimed a place in the second round against expectation: The world No21 from Essex romped to an 11-1, 9-4 lead against Aamir Atlas Khan when the 14th seed from Pakistan, ranked seven places higher, pulled up injured and conceded the match.
London-born left-hander Adrian Grant began his 2009 against qualifier Simon Rosner - and beat the top-ranked German 12-10, 12-10, 11-5.
"This is by far the biggest and most prestigious tournament there is - and the fact that all the top players are here speaks for itself," said the 28-year-old who broke into the world's top ten last month. I'd be speechless if I won it."
Londoner Peter Barker, also a left-hander, was the first through on the state-of-the-art all-glass court. The sixth seed took four games to overcome French qualifier Stephane Galifi 11-9, 4-11, 11-5, 11-2.
"Stephane was higher-ranked some time back, then took a couple of years off - so I knew he was one of the worst qualifiers to get. I was a bit edgy in the first two games, and he took advantage.
"Towards the back end of last season, I proved I can beat those above me on a one-off basis," explained the 25-year-old world No8. "Now I've got to keep improving and do it back-to-back."
RESULTS: internationalSPORTgroup British Open Squash Championships, Manchester
Men's 1st round:
Daryl Selby (ENG) bt [14] Aamir Atlas Khan (PAK) 11-1, 9-4 ret. (20m)
[8] Adrian Grant (ENG) bt [Q] Simon Rosner (GER) 12-10, 12-10, 11-5 (42m)
[15] Cameron Pilley (AUS) bt Farhan Mehboob (PAK) 13-11, 11-3, 11-9 (45m)
[4] Nick Matthew (ENG) bt [Q] Chris Simpson (ENG) 12-10, 11-2, 11-5 (41m)
[16] Ong Beng Hee (MAS) bt Davide Bianchetti (ITA) 11-8, 11-7, 7-11, 5-11, 11-3 (64m)
[6] Peter Barker (ENG) bt [Q] Stephane Galifi (FRA) 11-9, 4-11, 11-5, 11-2 (49m)
[Q] Kashif Shuja (NZL) bt [13] Mohamed El Shorbagy (EGY) 11-7, 13-11, 9-11, 2-11, 11-7 (57m)
[2] Gregory Gaultier (FRA) bt Saurav Ghosal (IND) 11-7, 11-6, 11-5 (38m)
More to follow ....