Kirsty McGuinness struck the crossbar with a free-kick early in the first half
Northern Ireland fell to a 1-0 defeat by Romania in the last of their three friendlies in Marbella.
Carmen Marcu's close-range effort following a Romanian corner on 63 minutes proved decisive.
NI went close to scoring an early opener when Kirsty McGuinness' free-kick struck the bar, while Lauren Wade saw a second-half effort saved.
Kenny Shiels' side had beaten the Faroe Islands and drawn with Switzerland in the other two games.
But they were unable to build on Sunday's impressive draw with the Swiss as they were edged out by a Romanian side who sit four places higher in the world rankings.
Northern Ireland almost took the lead in the 15th-minute when McGuinness' left-footed free-kick struck the top of the crossbar after Jackie Burns had produced a flying save at the other end to deny Romania a third-minute opener.
Nadene Caldwell also came close to opening the scoring but her well-struck right-footed effort from outside the box flew just wide.
The game's only goal arrived just after the hour when Northern Ireland failed to track the run of Marcu, who bundled the ball home from six yards.
Northern Ireland almost found the equaliser just four minutes later when Wade was denied by Romania keeper Camelia Ceasar after being slipped through by Rachel Furness.
Shiels' side are next in action on 8 April when they face Austria before hosting England four days later in a crunch World Cup qualifying double-header.
