Luke Evans claimed four wickets as Northamptonshire recorded back-to-back victories in the Second XI Championship for the first time in three years.
The tall paceman picked up 4-47 to help dismiss Surrey for 199 with 5.2 overs to spare at Campbell Park - giving the County a 73-run win.
The visitors were left to make 273 in 77 overs, but struggled from the start with only Akhil Patel - seventh man out for an excellent 97 - offering much resistance to Evans, who was well-supported by Gavin Baker (2-30), Lee Daggett (1-41) and Ricky Moore (1-23).
Tom Lancefield then bagged two late wickets without conceding a run to hasten the end.
Northamptonshire resumed on 187-6 in the morning session and were eventually dismissed for 244, thanks largely to a seventh-wicket stand worth 89 between Baker (55) and Gary Knight (48), plus 21 handy runs from Daggett.
The County hadn't won consecutive matches in the premier second team competition since 2010.