WELWYN GC disappointingly exited the FA Vase at the hands of opposition whom they had themselves beaten in the competition three seasons before.
But revenge was both sweet and deserved for an Ely City side, who although struggling in their own Eastern Counties League, have now won through five rounds of this season's Vase to reach the last 32.
Three seasons ago, the Citizens put Ely out in a replay, but despite a half-hour of late pressure, Adam Fisher's side couldn't force a second meeting with the Cambs side this time.
WGC never touched top form in this third round tie. Ely settled the better from the early minutes and although Jack Read had an early effort blocked for the Citizens and skipper Danny Payne was just wide with a 20 yard effort, it was the visitors playing the more cohesive football in the opening half-hour.
There was a warning on 28 minutes for WGC, when Ely's star man on the day Kelvin Enaro flashed a powerful effort just past a post.
The tricky winger tormented WGC's defence all afternoon and in particular, gave emergency full-back Taishan Griffith a tough time.
Manager Fisher attempted to remedy this by pushing Griffith forward in the second-half to a more accustomed position and bringing on Jason Coughlan, back with the club after four seasons, having signed from Ware.
But Coughlan's return debut lasted just seven minutes, when he pulled a calf muscle and had to be replaced himself by fit again Martin Standen, who was pushed upfront in a late onslaught.
Ely took a deserved lead on 38 minutes, when winger Matt Simpson made progress down the left and squared a pass to midfielder George Darling, in time and space to pick his shot, firing home through WGC keeper Jack Metcalfe's legs.
WGC were stunned, but were level in five minutes. Jack Read turned well 25 yards out and hit a powerful shot that Ely stand-in keeper Dean Grogan did well to turn away. Josh Bronti was first to the rebound, but was taken down from behind by Ely skipper Jamie Alsop and referee Parmenter immediately awarded the penalty.
Bronti, recovered after treatment, to take an emphatic spot-kick and maintain his 100 per cent record from the spot this season.
Ely effectively sealed their passage into the fourth round with a strong showing at the start of the second-half.
Five minutes after the restart and with there appearing no apparent danger, Ely substitute Craig Neal, introduced after the break, restored the Cambs side's lead with a lofted effort over Metcalfe that dropped into the far corner.
Before WGC could recover or settle again they were caught on the break for a third Ely goal, five minutes later.
The visitors broke from defending a WGC corner, midfielder Darling running 50 yards deep into home territory. Danny Payne failed to check his progress and Darling set up the dangerous Enaro for a low drive past Metcalfe for a 3-1 lead.
Again, WGC responded quickly and on 58 minutes reduced the arrears, John McGrandles rising impressively to a Jay Welsh free-kick to head down and past Grogan into the far corner, for 3-2.
From then, the Citizens attacked almost relentlessly for the final half-hour. But strong Ely defence, in front of keeper Grogan, restricted WGC to just one real opening, again from a set piece.
This time Luke Robins, the side's best attacking option on a disappointing afternoon, rose to another accurate Welsh free-kick to plant a header over the keeper and against the Ely crossbar - the closest WGC came to forcing a second meeting in Cambridgeshire, which, in truth, they didn't really deserve.
WGC: Metcalfe, Griffith, Boodhoo, McGrandles, Welsh, Payne, Long, Brettell (Coughlin 63, Standen 70), Bronti, Read (Chambers 87), Robins.