The 23-year-old, who committed his future to the club until 2026 on Thursday, produced a sublime header to open the scoring after nine minutes before Joe Thomson, brought into the starting side to replace an injured Dylan Sloan after netting twice against Newry City last weekend, doubled Larne’s advantage following good work from Mark Randall and Tomas Cosgrove.
Ronan Hale made it a nervy finish as he pounced after the hosts failed to deal with David Odumosu’s long ball over the top.
It helps cut the gap that leaders Linfield have opened up at the top, but David Healy’s men will look to restore their advantage once again when they take on Newry City at the Showgrounds on Saturday afternoon.
Premiership top scorer Ben Wilson had a magnificent chance to put Cliftonville ahead within two minutes as he glided through unchallenged after a Larne defensive lapse, but the 21-year-old couldn’t add to his astonishing tally of 15 goals and was denied by a fine save from Rohan Ferguson.
O’Neill then made the Reds pay the ultimate price for their lack of cutting edge and came close to netting a second soon after only for Odumosu to produce a superb reaction stop.
Larne were purring and came within inches of netting again as Randall’s strike from distance rattled off the crossbar after Ronan Doherty had been robbed of possession in midfield by Leroy Millar.
The crucial second that Lynch’s men undoubtedly deserved did come in the 36th minute – moments after Cliftonville had spurned a golden chance when Wilson’s pass towards Rory Hale was wayward with the Reds in a promising position following Cian Bolger’s slip – as Randall’s sweeping ball found its way to former captain Cosgrove on the right wing, who in turn laid the ball on a plate for Thomson with his effort taking a slight deflection off Luke Turner.
Lynch was able to welcome back Andy Ryan from injury with the Scottish striker coming off the bench after an hour to mark a first appearance since late-September.
Wilson struck the post after taking the ball wonderfully in his stride from a superb Doherty pass before he was flagged offside, but it showed a sign of Cliftonville’s attacking intent with Ronan Hale and Stephen Mallon introduced by Magilton.
Larne almost struck on the counter attack in the 68th minute with Ryan flicking a header into the path of O’Neill, who attempted to play in Millar, but brave defending from Kris Lowe ensured the hosts didn’t kill the game off.
Cliftonville almost found a route back into the contest when Turner’s cross was deflected onto his own post by former Reds defender Levi Ives.
Ferguson was then forced into a smart low save from Ronan Hale’s free-kick which made its way through the Larne wall.
Former Larne ace Hale did find the net in the 91st minute as he nodded home from close range after Ferguson palmed Odumosu’s long range ball into his path.
The victory extends Larne’s stunning home Premiership record to 16 consecutive matches unbeaten – their last defeat at Inver Park was almost a year ago against Coleraine.