Dunn conceded at Darlington after 523 consecutive minutes of league football, just short of the club record.
"It's nice to get records and it's been a team effort, but we got the result and that's the main thing," he told BBC Radio Northampton.
"I'll settle for the recent record. The main thing is to win and keep moving up the league."
Dunn holds the record in more recent times, with his sequence beating Keith Welch's 467 minutes in 2000, Andy Woodman's 422 minutes in 1997 and Mark Bunn's 405 minutes in 2008.
The all-time club record is six consecutive clean sheets.
Source: BBC Sport
Source: BBC Sport