Micas's strike just before half-time left Portugal a point away from a place in the semi-finals, ending Romania's own UEFA European Women's Under-19 Championship ambitions in the process.
A subdued game burst into life two minutes before the interval when the excellent Jéssica Silva, taking the ball on the right, delivered an inviting cross for Micas to turn in at the near post. Romania had chances to equalise, with Alexandra Lunca missing a glorious opportunity midway through the second period, but Portugal held on. A draw on Sunday against a Denmark side that have already won Group A would take them through.
With temperatures still high in Antalya neither team were keen to show their hands too early in a watchful first half. Romania put faith in a long-ball game that never concerned their opposition, while Portugal's ploy of using their wings enjoyed similarly scant return – until Jéssica Silva took possession two minutes before half-time. The match burst to life, with the second period barely recognisable from the first.
Anamaria Gorea headed just wide, Ştefania Vătafu, missed ever a threat from set pieces, missed by a whisker and Lunca squandered a glorious one-on-one, spearing wide with only the keeper to beat. Portugal had chances at the other end, with Jéssica Silva providing most of them as she hectored the Romania back line. They held firm, but it was not enough to deny Portugal a maiden victory at this level.