Albion pair Shane Duffy and Aaron Connolly suffered heartbreak against Portugal on a historic night in Faro.
Duffy was at the heart of a resolute Irish back line, which was only breached late on by a brace of headers from record-breaker Cristiano Ronaldo.
The Manchester United star made history as he headed his 110th goal to salvage a point for the home side and become the all-time leading scorer in international football.
He then headed the winner in stoppage time to break Irish hearts, and deny them precious points in their World Cup qualifying campaign.
Connolly was a threat on the break against a star-studded Portugal line-up in the Algarve, and won the corner which led to the John Egan’s goal just before half-time.
That came after Ronaldo saw his early penalty saved by 19-year-old Gavin Bazunu.
Jayson Molumby came on as a late substitute as Ireland’s World Cup hopes took a cruel blow, as they head into matches against Azerbaijan and Serbia in Dublin.
Elsewhere, Andi Zeqiri came off the bench for Switzerland in their 2-1 win over Greece; and Abdallah Sima came on for Senegal in their 2-0 win over Togo.