Cambridge eased past Northampton 3-1 to reach the FA Cup second round for the first time in four years.
Harvey Knibbs opened the scoring on 13 minutes, turning home from close range after Harrison Dunk’s cross was headed into his path by Joe Ironside.
Moments after Liam Roberts superbly tipped over an Adam May blast, Sam Smith did double Cambridge’s lead five minutes from the break at the second attempt after his initial effort had been kept out by Roberts.
Ben Worman’s goal three minutes after half time ended the game as a contest, the 20-year-old rattling an effort in off the post after being teed up by Ironside at the end of a fine move.
Roberts’ fine stop turned a Knibbs effort onto the bar as Cambridge continued to threaten, before the visitors pulled a goal back 16 minutes from the end when Danny Rose headed home Aaron McGown’s deep cross.
It was not enough to deny Cambridge, who go on to host Bradford or Exeter in round two.