Goals: Allen 86′ (pen) – MacDonald 12′, Gregory 79′.

Guernsey never really got going in this tough encounter but a superb first-half performance from debutant goalkeeper Callum Stanton ensured they came away with a credible scoreline against a strong Greenwich Borough side boasting plenty of pedigree.

Despite a promising opening, the Green Lions were second best to their powerful visitors for most of the contest and Ross Allen’s late penalty on his 200th start for the club never threatened to be more than a consolation that made the scoreline more respectable.

The Sarnians looked lively in the opening few minutes but it was the Cannons who fired first as Jack Sammoutis hit two shots from range inside 10 minutes. The first flashed narrowly wide and the second was held by Stanton – the stopper passing his first test in Guernsey shirt.

That was a threat of things to come, although the opener was a product of GFC’s own doing. Seb Skillen headed the ball back towards his defence but it fell straight into the path of Charlie MacDonald, who ran through and buried his effort past Stanton into the corner.

Stanton’s reflexes kept Guernsey in the contest in the first half and his most impressive piece of work came from an unbelievable double stop in the 18th minute. First, he got down to his right to parry Travis Gregory’s low effort across goal. The rebound fell to Bradley Pritchard in the six yard box. He should have buried it from point-blank range but Stanton’s lightening-quick reactions enabled him to get down to his right again and somehow tip the ball wide.

The hosts’ efforts during the contest were few and far between. Allen had the first, one of two free-kicks. On this occasion midway through the half, his effort bounced narrowly wide of Ben Bridle-Card’s left-hand post.

Stanton was called into action twice again with six minutes, first calmly plucking Dean Gunner’s looping header out of the air, then getting down to his right quickly to block to make another outstanding block from the same player as the Greenwich number six headed a corner towards goal.

Allen’s radar was now set and he hit the target with his second free-kick but it was comfortable for Bridle-Card to hold. GFC’s first chance from open play came courtesy of Matt Loaring’s header from Craig Young’s promising hook into the box from the right, but Loaring slightly mistimed his jump and made contact with the ball on his way down and send the header high and wide. Travis Gregory blazed high and wide from a promising position in the box in the last action of the half.

The Cannons thought they had doubled their lead within three minutes of the restart. Guernsey had failed to deal with sufficiently with Greenwich’s attack and the ball fell to Sammoutis 25 yards out. His low shot took a wicked deflection and nestled in the corner of Stanton’s goal. Greenwich celebrated, Guernsey’s defence protested and the assistant referee kept his flag down. However, after a discussion with the referee, it was deemed the ball had actually struck an offside Greenwich player on its way through. The strike was ruled out, but it didn’t stop the Garenne Stand giving the assistant referee plenty of grief for failing to spot the identity of the deflector in the first place.

Loaring came close 10 minutes into the half after he was found by substitute Paris Pereira’s pullback. It was well struck by Loaring from distance, but took a deflection as it whistled narrowly over the bar.

Within two minutes of that, Young had curled high and wide from the resulting corner, and Pritchard headed well wide on the stretch at the other end.

Borough continued to threaten for a second and Gregory’s stab at goal crept wide of the near post from MacDonald’s left-wing centre.

That came with 20 minutes remaining, and with just over 10 left, a second Greenwich goal looked to have sealed the contest. Alex Le Prevost had come on for his first appearance since January and his lack of sharpness was exposed as Gregory easily outstripped him from pace as they chased a long ball. He cut back onto his right foot and tucked it past Stanton.

It looked to be game over, but Guernsey grabbed a consolation late in the game. Allen’s fancy footwork got him into the right-hand side of the area. He was tripped and stepped up to take the resultant spot-kick, burying it in the right corner to halve the deficit.

It set up a potential exciting finish, but Greenwich never looked in danger of conceding an equaliser and headed back to the mainland with all three points.

Borough leapfrogged the Green Lions as a result of their triumph, with Vance’s side having taken three points from their opening three matches and dropping one place to 14th.

The rest of the Bostik South results were as follows: Ashford United 2-5 VCD Athletic, Carshalton Athletic 4-1 Shoreham, Cray Wanderers 4-0 Molesey, East Grinstead Town 0-5 Corinthian-Casuals, Herne Bay 3-1 Chipstead, Lewes 2-2 Sittingbourne, Phoenix Sports 2-0 Hythe Town, Ramsgate 1-2 Hastings United, Thamesmead Town 5-0 Horsham, Walton Casuals 4-3 Faversham Town, Whyteleafe 3-1 South Park.

Greenwich Borough: Ben Bridle-Card, Tom Carlse (Lewis Clarke 77′), Mark Phillips (c), Dean Gunner, Travis Gregory, Charlie MacDonald (Jesse Darko 73′), Jack Sammoutis (Peter Sweeney 85′), Liam Hickey, Bradley Pritchard, Ali Fuseine, Sam Corne. Not used: Kaka Dembele, Connor Hunte.

Booked: Phillips.