Dublin-born Dean Ebbe led The New Saints to a 3-1 victory in their JD Sports Welsh Cup tie against Caernarfon Town.
The former Shamrock Rovers striker scored twice on his full debut for Saints, who moved into the quarter-finals thanks to a 2-0 victory in front of almost 1,500 spectators at the Oval.
Ebbe, 23, has played for number of teams in his native Ireland – Longford Town, Athlone Town, Cabinteely and Leinster Senior League champions Bluebell United.
The 6ft 2ins hit-man moved to Scottish club Inverness Caledonian Thistle in 2017 and scored in none consecutive matches for their reserves.
He has switched from Scotland to Welsh Premier League champions TNS, who are aiming to regain the Welsh Cup after losing in the final against Bala last season.
Ebbe struck with his first goal after four minutes and that was the only goal of the first half. He struck with a second goal three minutes after half-time.
Cymru Alliance leaders Caernarfon had a lot of possession, but TNS were clinical with their finishing.
Saints looked comfortable, but Caernarfon are a team with plenty of of spirit and character. They pulled a goal back after 77 minutes when Darren Thomas produced a good finish from a Jamie Breese cross.
Saints made one change from their starting line-up in the Nathaniel MG Cup final, when they defeated Cardiff Met 1-0, with Ebbe called up for his debut after going on from as a substitute. Jon Routledge was on the bench.
TNS have appeared in five of the last six JD Welsh Cup finals, winning four times and then going down against Bala.
Caernarfon are pushing hard for promotion this season and that is their priority. They are six points clear at the top of the Alliance, ahead of Guilsfield in second place.
Ebbe was the star of the TNS showing, while Aaron Edwards added their third goal a minute into injury time.
New signing Kevin Kauber, a 22-year-old Estonian under-23 international, went on for Saints from the bench.
Caernarfon gambled during injury time by sending on three substitutes, but at 3-1 the Saints had clinched victory and are the first time through to the last eight.
JD Welsh Cup fourth round draw:
Friday, January 26: Caernarfon Town 1, The New Saints 3.
Saturday, January 27: Pontypridd Town v Penydarren Boys and Girls FC (1.30pm).
Saturday, January 27: Airbus Broughton v Carmarthen Town, Cardiff Metropolitan v Aberystwyth Town, Connah’s Quay Nomads v Porthmadog, Flint Town United v Newtown, Llanrhaeadr Ym Mochnant v Bangor City (all 2.30pm).
Saturday, January 27: Llandudno v Ruthin Town (5.15pm, live on S4C).
Most of the action this weekend is in the Huws Gray and JD Welsh cups. There were five Huws Gray Alliance clubs looking to progress in the JD Welsh cup, although Caernarfon went down against Saints.
The other ties involving Alliance teams are : Airbus Broughton v Carmarthen, CQ Nomads v Porthmadog, Flint Town United v Newtown, Llandudno v Ruthin Town.
There are two games in the Huws Gray Cup on Saturday: Llandudno Junction v Rhyl (1.30pm), Holyhead Hotspur v Guilsfield.
The three league fixtures scheduled are: FC Queens Park v Denbigh Town, Gresford Athletic v Holywell Town, Penrhyncoch v Caersws.
