HISTORY was made when goals from Sean Brettell and Joel Norris at the end of each half secured the Citizens the SSML Div 1 Cup, to go with the league title trophy presented to them three days earlier.
The league and cup double is the first achieved by the club in its 94 year history.
Adam Fisher's side sparked a night of celebration at Herns Lane, when they returned with a second trophy inside four days and the now the side look forward to the sterner tests of the SSML Premier Division next season - a status they lost seven seasons ago.
In the end, WGC were worthy winners of a cup final, played at Langford FC and watched by a crowd of 250 - 90 per cent of whom were supporting the Citizens.
A fairly ordinary first-half offered little in the way of chances, although their Luton opponents shaded it in terms of possession.
Jason Caswell had WGC's first opportunity, doing well to dispossess Crawley Green keeper Bull, but from a tight angle, could only find the side netting.
Joel Norris, needing a hat-trick to make him the SSML's leading scorer in all divisions, tried a dipping effort from 20 yards, just wide.
Crawley Green's Craig Savage, a player who once interested WGC, got in a goal-saving tackle on Caswell, when the striker latched onto a long Joe Croft goal-kick, but most of the first-half action was condensed into the final five minutes.
Croft rushed headlong from goal to claim at Crawley Green striker Liam Toomey's feet, but the forward got away from the WGC keeper's attentions, to shoot narrowly across the face of goal.
In the next minute, Croft did much better with a vital save with his outstretched leg to divert away a Sam Halfpenny shot that threatened to give Crawley Green the lead.
But in the next raid, it was WGC who took the lead, a little against the run of play. Caswell was fouled on the edge of the area and set-piece expert Brettell stepped up to curl a delightful left-foot effort beyond a static Bull in the final attack of the half.
But if WGC were a little fortunate to be ahead at the break, there was no denying that they deserved the trophy on their second-half showing.
Manager Fisher introduced Craig Arnott for defender Sam Perrin at the break and backed by the tireless running of Sam James and the tenacious tackling of Juan Cifuentes, WGC dominated midfield and the rest of the game.
Norris volleyed another chance across the face of goal, after neat build-up involving Cifuentes and Caswell, while Brettell lofted a chance of a personal second over the top with a well struck drive.
The best effort of the game came from the outstanding James, intercepting a clearance and striking a fearsome volley that beat Bull and must have shaved the paint off the Crawley Green crossbar as it just went over.
The Luton side had one clear chance eight minutes from the end. Jack Downes was given the benefit of the doubt when looking offside and crossed for Sam Peveral to put Crawley Green's best chance of the entire final wide from a few yards.
It was a miss they were soon to regret. WGC were immediately back on the offensive and netted a clinching second three minutes from the end, when Cifuentes found top scorer Norris.
He held off two defenders as he jockeyed for position, getting the ball onto his right foot to rifle a trademark, low finish past Bull to clinch the trophy and his and the current team's place in the Welwyn GC FC history books.
WGC: Croft, Perrin (Arnott C 45), Kenna, Boodhoo, Lovell, Cato (Ross 75), James, Cifuentes, Brettell, Caswell, Norris (Dekanski 90).