Norway scored three times in the opening 20 minutes as Northern Ireland’s makeshift defence was made to pay in a 5-1 Nations League defeat at Windsor Park.
In Ian Baraclough’s first home game in charge, Paddy McNair’s fifth-minute strike cancelled out Mohamed Elyounoussi’s opener only for Erling Haaland and Alexander Sorloth to put Norway 3-1 up at half-time.
Second-half goals from Sorloth and Haaland then saw Northern Ireland, missing Jonny Evans and Jamal Lewis, concede five at home for the first time since 2003 in Nations League group B1.
Romania earned a narrow 3-2 victory in a hard-fought match with Austria in Northern Ireland’s group, Alexandru Maxim’s 69th-minute goal proving decisive.
Scotland overcame a difficult makeshift Czech Republic team to win 2-1 in Olomouc in group B2.
After the hosts’ squad had been stood down amid coronavirus concerns, the team contained nine debutants but managed to take a surprise lead through Jakub Pesek in the 11th minute.
Lyndon Dykes levelled with his first goal for Scotland in the 27th minute before Ryan Christie scored his second spot-kick in two games just after the half-time break.
Israel and Slovakia played out a 1-1 draw, substitute Ilay Elmkies with a late Israel equaliser to cancel out Michal Duris’ goal.
Elsewhere, Italy went top of group A1 with a 1-0 victory over Holland, Inter Milan midfielder Nicolo Barella heading home on the stroke of half-time.
In the same group, Poland secured a 2-1 win over Bosnia-Herzegovina with goals from Kamil Glik and West Brom winger Kamil Grosicki.
In group C4, Belarus secured an important 2-1 win in Kazakhstan while Lithuania won 1-0 in Albania.