There was absolutely no indication that the final scoreline would produce a three-goal margin as, for most of the game, Craigroyston matched their visitors and all that was lacking was a killer touch in front of goal.
The game had been in doubt because of a waterlogged pitch although the surface was superb and a credit to the Craigroyston head groundsman, Rab Currie, who had the pitch in magnificent condition.
Craigroyston started as the more offensive side and Yubong Umotong tested Iain Gordon with a low shot before Kevin Robertson further tested the goalkeeper with an effort which came off his chest. A Stevie Manson corner was headed over by Steven Finlayson then Manson brought out a fine diving save from the busy Gordon.
However, Leith responded with a 25-yard shot from Gavin Tainsh which went wide of the target and a similar effort from William Bremner also flew past the post. A jinking run from Manson ended with another good shot which Gordon gathered at the second attempt then Kyle Hay fired a first time left foot volley narrowly over the crossbar. Craigroyston missed a glorious opportunity to take the lead five minutes before the interval when Manson somehow lifted the ball high over the bar from six yards out with Gordon stranded. At the other end Michael Atai made a good blocking save from Jack Combe and the teams finished the first half goal-less.
But it took only seven minutes of the second period for Leith to make the crucial breakthrough. Darren Lavery delivered a right wing cross with pace and Combe rose to bullet a header behind Atai from eight yards.
Umotong almost equalised with a curling 20-yard free-kick then the same player had a 25-yard shot tipped over the bar by the alert Gordon. Umotong looked certain to put the ball in the net midway through the second half until he was halted by a quite superb tackle from Neil Lowson.
Leith went two ahead in the 80th minute when Tainsh picked out Paul Coleman some 35 yards from goal and the midfield player did not hesitate as he fired a magnificent left foot shot into the top corner leaving Atai rooted to the spot. It was a goal fit to grace any level of football. Only four minutes later the result was put beyond doubt when another penetrating cross from Tainsh was met by Bremner at the front post and he powered an unstoppable header behind Atai.
Leith have now won nine of their ten league games and are five ahead of their nearest challengers, Easthouses Lily, although Gretna 2008 have three games in hand and trail Leith by eight points.
Willie McFarlane, the delighted Leith manager, said: "I thought that it was a typical derby with some good hard tackles. Craigroyston shaded the first half and could easily have been a couple of goals up.
"We changed our shape and moved four or five players then we began to get a grip of the game and dominated in spells. Although 3-0 probably flattered us it was great to get a clean sheet."
Meanwhile, the Craigroyston manager, George Bowmaker, was still relatively upbeat despite the defeat. "I was happy with our performance and I can see improvement in the four weeks that Jock McGraw and I have been here," he said. "There is certainly no doom and gloom in our dressing room."
Craigroyston: Atai, Sproule, R. Cameron, Robertson, Pullen, McKenzie, Manson, Hay, Umotong, Jones, Finlayson (Robertson, 72). Subs: Binnie, Hare, Fallon, J. Cameron.
Leith Athletic: Gordon, C. Barrie, Burstow (S. Barrie, 72), Lynch, Lowson, Black, Tainsh, Bremner (Smith, 87), Combe, Lavery, Coleman (Law, 85). Subs: Campbell, Thom.
Referee: G. MacVicar.
Leith Athletic 3