Dong Gook Lee finally grabbed his first Middlesbrough goal as the 2004 winners rode their luck to beat Northampton 2-0 in the Carling Cup.
The Cobblers almost took a shock lead in the second-round clash when Brad Johnson's drive was parried by Boro keeper Brad Jones into the path of Ian Henderson, who clattered the woodwork.
Boro were wasteful in attack but the frustration in the sparsely-populated stands was lifted in the 53rd minute when Fabio Rochemback fired home a low free-kick from 35 yards after Johnson's foul on Lee.
Lee then took his chance in the 66th minute when he was played in by Stewart Downing and produced a clinical finish.
Henderson's close-range shot was booted off the line by Luke Young - but Boro should have had a third on 76 when sub Mido headed an Adam Johnson cross from the right against the bar from close range.