Monkstown's Sean Desmond produced a little bit of magic to stay alive before going on to beat international Tiarnan McLarnon on the 19th to reach the semi-finals of the Pierse Motors VW sponsored South of Ireland Amateur Open at Lahinch.

Playing in just his third "South", the 21-year Munster Students champion endured a rollercoaster afternoon at the sun-splashed Co Clare links before emerging triumphant to face Co Sligo's Sean Flanagan for a place in the final.

Carton House's Keith Egan continued his impressive passage when he dispatched Kinsale international John Murphy 6&4 and will now take on Newlands' Jake Whelan, who was a 3&2 winner over leading qualifier Hugh Foley from Royal Dublin.

Flanagan won the North three years ago while Egan was a semi-finalist at Lahinch in 2016 and former Leinster interprovincial Whelan has two "major" semis on his CV.

But Desmond is the real surprise package in the last four and his win over McLarnon, a former Irish Close winner, was certainly a surprise.

Having shot five-under for 17 holes to beat Castleknock’s Paul Coughlan 2&1 in the morning, he was 3-up after 10 holes against McLarnon but went to the 14th all square as the Ulster star made huge putts to win the 11th and 12th and then took the 13th with a conceded birdie.

But the Massereene man's short-range putting proved his Achilles' heel in the end.

The Munster Students champion won the 15th in par to go in front, escaped with a half in bogeys at the 16th where McLarnon missed a four-footer and then looked to be on the back foot when he drove into a bad lie right at the 17th and his hack out squirted right into deeper trouble.

McLarnon fired his approach stone dead to square the match, and he looked odds on to progress when Desmond pulled his second close to the wall left of the 18th.

McLarnon's slinging approach cleared the trouble on the right and finished just 25 feet above the hole, setting up an eagle chance and a near certain birdie.

Forced to go for broke, Desmond played an audacious parachute shot to 18 inches to halve the hole in birdie, then won with a par at the 19th as McLarnon's approach from rough 30 yards left of the fairway ran through the back, and he missed a three-footer to extend the match.

"I am delighted," Desmond said. "I didn't expect it at all. I played really well against Paul Coughlan in the morning and was four or five-under. And this afternoon it could have gone either way.

"On 18, he was going to make birdie so I thought I might as well go for the shot and it came off. It's pretty cool to be in the semi-finals."

Of the four semi-finalists, former international Flanagan (23) is the only one with a "major" to his name following his win over McLarnon in the North of Ireland final at Portstewart three years ago.

Whelan (24) reached the semi-finals of the "Close" at Ballyliffin in 2016 and the last four in the "West" in 2017.

And he will need to show the same steel he showed against Foley when he faces 2016 South of Ireland semi-finalist Egan.

Tied for 15th in the West, Egan was tied third in the Munster Strokeplay, and then contended for the Irish Amateur Open on his return to Rosses Point before a closing 81 saw him slip to joint 32nd.

The Dubliner lost on the 19th in the semi-finals to eventual champion Stuart Grehan in 2016 and he's in the running for a spot on the Irish team for September's Home Internationals at Lahinch.

After a consistent campaign, he's within striking distance of the top-three in the Bridgestone Order of Merit who gain automatic selection.

Whatever happens, a new name will go on the famous silver trophy and if the last two days are any indication, it promises to be another highly entertaining final day.

South of Ireland Amateur Open Championship, Lahinch GC (sponsored by Pierse Motors VW)

Semi-finals:

(8.30am) Jake Whelan (Newlands) v Keith Egan (Carton House);

(8.45am) Sean Flanagan (Portmarnock) v Sean Desmond (Monkstown).

Quarter Finals

J Whelan bt H Foley 3&2;

K Egan bt J Murphy 6&4;

S Flanagan bt E Griffin 2&1;

S Desmond bt T McLarnon 19th.

Third round

J Whelan (Newlands) bt M McClean (Malone) 1 Hole;

H Foley (Royal Dublin) bt P O'Keeffe (Douglas) 2&1;

K Egan (Carton House) bt K McCormack (Portarlington) 2 Holes;

J Murphy (Kinsale) bt A Hill (Athenry) 5&4;

E Griffin (Waterford) bt J Rackard (Enniscorthy) 7&6;

S Flanagan (Portmarnock) bt P Conroy (Enniscorthy) 1 Hole;

S Desmond (Monkstown) bt P Coughlan (Castleknock) 2&1;

T McLarnon (Massereene) bt C Butler (Kinsale) 4&2.