I've always feared teams.
But while McClean deserves a lot of credit, Shane Duffy was a wall at the back for Ireland and unfortunately misses the first leg of the play-off through suspension.
Ireland are among the four bottom seeds going into the draw. It helped that they had Aaron Ramsey and Joe Allen prompting in midfield.
Italy, Greece, Denmark and Croatia make up the rest of the playoff possibilities.
Say what you like about the style of football played, and plenty do, but the Republic of Ireland reaching the play-offs is a considerable achievement too.
This game saw 58 aerial duels contested - the most in a single game during in this UEFA Qualification campaign for World Cup 2018.
In Sunday's prematch news conference, O'Neill hinted at a similar strategy as Ireland's defeat of Italy at Euro 2016, where his team dug in and waited for their moment to come through Robbie Brady's victor.
Speaking ahead of the game, Ireland manager Martin O'Neill suggested the players would love to get to Russian Federation for Coleman. They have so much big game experience and intelligence now both from qualifcation and a major tournament.
O'Neill's men remained resolute and showed the same defensive solidity they did before the break to see out a famous victory and break Welsh hearts, but their own journey is not over yet and they will be without captain Meyler for the first leg of the playoffs after his stoppage-time booking.
World number one right now is Germany [1,661 points].
As for their conquerors, a gracious Coleman wished the Irish well for the next stage of their World Cup quest, saying: "Martin O'Neill has done a great job and good luck to them".
After that, it was all about digging in and seeing the game home.
Croatia would be a tricky draw for the Republic, despite Iceland causing an upset and winning Group I in a group with Ukraine, Turkey, Finland and Kosovo. And the players will not give up, that's the point.
Ireland are not a side any nation in the play-offs will want to come against. "And so we go to the play-offs". O'Neill has identified a reliable replacement for Irish veteran John O'Shea in Duffy, whose performances of late in a green shirt will have Brighton shielding interest from other Premier League clubs. It's great to see them back at the top again.
But also consider this; the week before the Switzerland game, Duffy scored a late victor to give a 10-man Blackburn a 1-0 victory over Judge's Brentford at Griffin Park.
They collected an fantastic 11 points on their travels, not losing even once, with victories in Moldova and away to serious rivals Austria and Wales.
O'Neill's side find out their opponents next Tuesday and he could not hide his pride at the full-time whistle.
"Please don't take me home" indeed, as the song goes.
They went close, but not close enough, and as the game finished, Wales were left to reflect on yet another agonising moment in their history.
Wales skipper Ashley Williams lost possession on the edge of his penalty area and Jeff Hendrick crossed for McClean to slam home his fourth goal of the campaign.