JAMIE McGonigle bagged a brace as Derry City totally dismantled a stunned St Patrick's Athletic at Richmond Park to reinforce their title credentials and move three points clear at the top.
It was the Dungiven striker's fifth goal in two games to take his season's tally to nine and he had goals disallowed in either half for offside as Derry left the Saints shell-shocked.
It was a masterclass team display from Ruaidhri Higgins' troops who blitzed the Dubliners with three first half goals.
Considering the Saints boasted the league's joint meanest defence with just eight goals conceded prior to kick-off, it was a significant win which opened up a 10 point gap between the teams.
Indeed, it was the perfect night for the ruthless Brandywell outfit with Matty Smith finally getting off the mark with his first goal against his former club after just four minutes.
McGonigle had the ball in the back of the net four minutes later as he chipped the ball over the keeper and into the top corner but it was harshly ruled out for offside.
Derry doubled their lead on the half hour mark when Smith's strike was diverted into the net by the outstretched leg of McGonigle who continued his rich goalscoring form.
McGonigle, the league's top scorer, netted his ninth of the campaign with a clinical finish on 42 minutes after a sublime pass from the impressive Brandon Kavanagh.
And Cameron Dummigan scored the pick of the bunch with a fantastic curling strike from 30 yards just after the hour mark to seal a remarkable victory for the league leaders.
Ruaidhri Higgins opted for an unchanged starting XI from the team which thrashed UCD 7-1 in their last outing.
However, a change of formation saw the visitors line out with four at the back with Tim Clancy opting for a back three which was run ragged in the opening stages.
Derry started confidently and deservedly broke the deadlock with just four minutes on the clock after Neil Forrester gave away possession deep inside the Saints' half.
The ball was worked into Kavanagh who found the feet of Smith with a deft cushioned pass inside the 18 yard box and the ex-Dundee United man took a touch before poking it into the corner of the net to finally get off the mark for his new club.
Four minutes later St Pat's were fortunate not to be two goals behind as McGonigle's goal was harshly disallowed for offside despite the ball coming off a home defender before falling kindly to the league's top scorer.
Derry were totally dominant in the opening stages and Pat's were clearly rattled by a blistering start from Higgins troops who were buoyed by their biggest league win since 1991 last weekend.
Derry almost took advantage of another unforced error from St Pat's who gifted possession to Will Patching on 15 minutes but the City midfielder fired wide of the mark with McGonigle begging for the ball in a decent position inside the box.
The Dubliners' first attempt on goal arrived on 20 minutes as Darragh Burns latched onto the ball in the middle of the park before finding Doyle on the edge of the box. The ex-Bolton striker lobbed his cross towards the back post where Anto Breslin powered his header into the hands of Maher.
Burns was threatening to break in a potentially dangerous attack from the Inchicore men but Patrick McEleney made a brilliantly timed defensive challenge to put an end to the move on 26 minutes.
Derry doubled their lead on the half hour mark after a brilliant piece of skill from Patching who twice turned two Saints defenders just inside the 18 yard box before laying it into the path of Smith.
The Scotsman's shot from an angle was going wide of the far post but McGonigle showed his poacher's instinct by directing the ball into the net for his eighth goal of the season.
Moments later St Pat's should've pulled one back from a corner kick when Joe Redmond headed Billy King's cross back across goal but Jack Scott swung his foot at the chance and fired harmlessly over at the back post.
Derry were on the rampage and when a stunning reverse pass from Kavanagh found the run of McGonigle through the middle, the City striker made no mistake with a clinical finish into the corner of the net with three minutes to go in the half.
Clancy's men were simply blown away by the visitors who were out of sight at the interval following a magnificent display. And it could've been worse but for that earlier disallowed strike from McGonigle.
St Pat's made a change at the interval with Ronan Coughlan replacing Scott as the Dubliners reverted to a 4-4-2 formation.
Derry had the ball in the back of the net three minutes after the restart from a cleverly worked corner kick played short into the feet of McEleney. The Shantallow man found the unmarked Kavanagh who struck the foot of the post.
When the ball rebounded off the woodwork it struck McGonigle and found the net but the effort was correctly flagged offside.
It mattered little as Derry made it four on 62 minutes in stunning fashion. St Pat's again surrendered possession inside their own half and when Patching, who made a lung bursting run towards goal, laid the ball off to Dummigan the Lurgan man curled a sensational strike into the net from 30 yards.
At the other end Shane McEleney made a superb sliding tackle to deny Adam O'Reilly a strike on goal from close range but the home side were shell-shocked as Clancy again went to his bench in a desperate attempt to turn the tide.
However, it wasn't to be as Derry ran out comfortable winners and sent out an ominous warning to champions, Shamrock Rovers.
St Pat's Athletic: J. Anang; J. Scott (R. Coughlan h-t, K. Corbally 83), J. Redmond, T. Grivosti, I. Bermingham; A. Breslin, D. Burns (T. Owolabi 64), C. Forrester, B. King (J. McClelland 64), E. Doyle, A. O'Reilly; Subs Not Used D. Odumosu, B McCormack S. Curtis, R. Fay, K. Robinson.
Derry City: B. Maher: S. McEleney, E. Toal, C. McJannet; R. Boyce (D. Lafferty 82) C. Dummigan, W. Patching ( C. Coll 82), M. Smith; B. Kavanagh (E. McLaughlin 69), P. McEleney (J. Thomson 69) J. McGonigle (J. Akintunde 76); Subs Not Used - N. Gartside, C. Porter, D. McCallion, L. Mullan.
Referee - Rob Hennessy.