A win over Slovakia in Glasgow could move Scotland into the play off place, although a draw might be a better result for Ireland. Do that and they finish on 19 points overall but 13 points to go towards the playoff standings. We have a huge test on Monday night against the Republic of Ireland.
And if he helps O'Neill's side go on to clinch a place at the World Cup finals in Russian Federation, he is unlikely to ever have to buy a drink in his native Waterford again. The runner-up with the lowest number of points will miss out on a play-off spot. Teams would take points off each other.
You know the drill by now - six wins, two draws, three goals conceded. Yet Group D leaders Serbia are in pole position and at home to Georgia.
Together Stronger, the song by the Manic Street Preachers, says: 'When Gareth Bale plays, we can beat any side.' If they are going to book their place in Russian Federation next summer, it's now all about what they can do without their superstar.
The results elsewhere will have a massive impact the fate of the team that ends up finishing second in the group, and it means supporters up and down Europe have been endlessly updating their list of scenarios based on each result.
Chris Coleman's men only need a point against Ireland to advance to the play-offs, whereas anything less than a win will see the boys in green eliminated early.
The second half was a damp squib, only livened up by the spark from debutant Maguire off the bench and an injury-time red card for Alexandru Gatcan, for a head-butt on sub Harry Arter. But, although they are still to win a Group D tie, Georgia have drawn five of their eight matches including their showdown in Cardiff.
Wales were on a charge to qualify to Russian Federation via a play-off by finishing second on the group but the defeat of Serbia means they can seal an automatic qualification in the last match should the Serbians fail to register a win.
Daryl Murphy is averaging a goal every 55 minutes in World Cup qualifying for Ireland (three goals scored in 166 minutes).
Should they get that far, once again there are some hard sides in the running - Ireland would do well to focus on winning against Moldova for now, and think about qualifying permutations later.
But Murphy made a very strong case last night with his display.
Against Georgia, Wales played a four-man defence of dependable veterans in James Chester, Ashley Williams, Chris Gunter and Ben Davies and, while Williams has suffered heavy criticism as part of Everton's poor start to the season, he was man of the match in Tbilisi. Can they do it?