Cambridge United 2 Aldershot Town 1
Boylan 60, Fortune-West 85 Dixon 31
LEO FORTUNE-WEST'S 85th minute goal sent Cambridge United into the second round.
The U's went behind to a Jonny Dixon strike in the first half but goals from Lee Boylan and Fortune-West gave the home side a deserved win.
Delighted Cambridge assistant manager Alan Lewer said: "I thought we were magnificent and some of the football we played was excellent."
He added: "It's the league that we want but this is a nice little bit of a run for the players to go on."
In the seventh minute Nikki Bull in the Aldershot goal made a great save, diving to the right to block Scott Rendell's close-range effort.
Joel Grant went close for Aldershot when he ran from midfield and tried his luck from the edge of the area but his shot flew over the bar.
Michael Morrison attempted a shot from over 35 yards which Bull tipped over the bar with a superb one-handed save.
In the 31st minute and against the run of play, Aldershot took the lead. Joel Grant flicked on a long ball and Dixon beat the offside trap to slot the ball home.
Cambridge's pressure paid off on the hour mark when Darryl Knights' right-wing cross was headed home by Boylan from six yards.
Aldershot had a chance to retake the lead in the 74th minute but sub John Grant put Dixon's pass over the bar.
And with only five minutes to go Fortune-West slotted the ball into an open net after Bull failed to deal with Stephen Reed's free-kick.
Aldershot's Scott Davies was sent off following a confrontation with Fortune-West.
Shots boss Gary Waddock said: "They're a good side and they put us under pressure."
CAMBRIDGE: Potter 7, Reed 7, Peters 7, Albrighton 6 (Hoyte 19, 6), Gleeson 6, Wolleaston 6, Rendell 7 (Fortune-West 81, 7), Boylan 9, Pitt 7, Morrison 7, Knights 7 (Hyen 86, 6). Subs not used: Willmott, McShane.
ALDERSHOT: Bull 8, Straker 6, Newman 6 (Charles 44, 7), Day 6, Soares 6 (Chalmers 71, 6), Elvins 6 (John Grant 60, 7), Dixon 7, Davies 6, Harding 6, Gier 6, Joel Grant 7. Subs not used: Hodson, Jaimez-Ruiz
STAR MAN: Lee Boylan (Cambridge)
REF RATING: Gary Sutton 5/10