In Heimir Hallgrimsson's first game in charge, Ireland were outplayed by their neighbours from across the Irish Sea and are already playing catch up in Group B2.
Match preview
Many fans and neutrals will have underlined Ireland vs. England as one of the standout games of this Nations League campaign, in what was a first competitive meeting in over three decades.
Ireland were largely disappointing though, as England cruised to a 2-0 win in Dublin, and in a nightmare scenario for the Irish supporters, it was the two most unpopular people inside the Aviva Stadium who got the goals.
Declan Rice, who switched allegiance to England after representing Ireland in friendlies, and Jack Grealish, an Irish youth international, scored the first-half goals to put the game out of reach early on.
Had it not been for the heroics of Caoimhin Kelleher in the second half, the scoreline could have been much uglier for the Irish too, as the Liverpool stopper was on hand to keep England at bay numerous times in the second half.
That extended Ireland's run to nine defeats in 14 matches, with only three of those ending in victory, two of which came against Gibraltar.
Another defeat at home here would make relegation a very likely outcome, with trips to Wembley and Athens unlikely to end favourably.
After three straight third-place finishes in League B groups, Ireland's imminent future in the second tier could be under threat unless Hallgrimsson can make an immediate impact against the less powerful sides in the group.
That starts with Greece, but Ireland's recent record against their upcoming visitors is far from ideal, with one draw and four defeats in the five encounters between the two nations.
Their only previous competitive meetings came last year in Euro 2024 qualifying, as Greece came out on top in both, including winning 2-0 here in Dublin.
Greece would go on to fall at the final hurdle in their attempts to reach a first major tournament in a decade, losing to Georgia in the playoff final on penalties.
That major disappointment saw Gus Poyet relieved of his duties and replaced by Ivan Jovanovic, who made the perfect start in charge by beating Finland 3-0 on Saturday.
The new manager made a few big calls with his team selection, but it paid off, most notably starting Fotis Ioannidis up front instead of Benfica's Vangelis Pavlidis, as the Panathinaikos striker netted a brace.
After needing three attempts to make it out of League C, Greece are now in the second tier for the first time, and could make the perfect start ahead of a tricky test against England in October.
Republic of Ireland Nations League form:
L
Republic of Ireland form (all competitions):
D
D
L
W
L
L
Greece Nations League form:
W
Greece form (all competitions):
D
W
L
L
W
W
Team News
Ireland captain Seamus Coleman is set to miss this encounter after hobbling off with a foot injury following a collision with Harry Maguire on Saturday.
Coleman's Everton teammate Jake O'Brien could be the man to come in if Hallgrimsson sticks with a three-at-the-back system, slotting in as a more orthodox central option.
Evan Ferguson made his first appearance for club or country since March, but a lack of match fitness may see him only start as a substitute again.
As many as seven of the starters who lost to Greece last October could play some part in this one, but Josh Cullen will not, as the Burnley midfielder is currently sidelined through injury.
Jovanovic surprised everyone by choosing Ioannidis over Pavlidis at the weekend, but his two-goal performance should see him retain his place up front for Greece.
Anastasios Chatzigiovanis was another surprise inclusion considering he has barely featured for Eyupspor so far this season, and after being subbed at half time, he could drop to the bench here, with Christos Tzolis and Giannis Konstantelias the candidates to replace him.
Despite not playing at club level, Odysseas Vlachodimos retained his place in goal ahead of young Olympiacos stopper Konstantinos Tzolakis in the win over Finland, and that clean sheet should see him start again.
Many regulars were left out by the new manager though, as there was no place in the squad for Dimitris Kourbelis after his move to Saudi Arabia, and for defensive trio George Baldock, Panagiotis Retsos and Giorgos Kyriakopoulos.
Republic of Ireland possible starting lineup:
Kelleher; Doherty, O'Brien, Collins, O'Shea, Brady; Molumby, Smallbone; Ogbene, Idah, Szmodics
Greece possible starting lineup:
Vlachodimos; Rota, Mavropanos, Koulierakis, Tsimikas; Mantalos, Bouchalakis, Bakasetas; Konstantelias, Ioannidis, Pelkas
We say: Republic of Ireland 0-1 Greece
If Greece want any chance of competing with England for promotion, home and away wins against both Ireland and Finland are likely going to be necessary.