Northern Ireland's World Cup hopes suffered a huge blow as they were well beaten by Portugal at Inver Park in the first leg of their play-off semi-final.

The visitors took control with three first-half goals after Telma Encarnacao broke the deadlock on eight minutes, before Jessica Silva doubled the lead and Rebecca Holloway scored an own goal.

It was a more positive second half from Northern Ireland after Portugal were reduced to 10 players when Catarina Amado was given her marching orders in the 64th minute.

However, Fatima Pinto extended their lead with seven minutes left, before Cora Chambers was shown a straight red card for pulling Carolina Correia's hair in the fifth minute of added time.

The sides will meet again in Portimao on Tuesday (19:45 BST) but it will be an uphill task for NI to progress, with the likely opponents Iceland, who also have a four-goal advantage over Croatia following the first leg.

Portugal started brightly and won an early penalty when debutant Jane McMaster was adjudged to have handled the ball while she attempted to prevent Silva from connecting with Andreia Jacinto's low cross to the back post.

Encarnacao confidently sent her spot-kick into the bottom right-hand corner to give the visitors an eighth-minute lead.

Tatiana Pinto then curled a shot on to the roof of the net as Portugal looked to build on their early advantage.

Michael McArdle's side reacted well to the early setback and Rebecca McKenna was just inches away from connecting with Ellie Mason's inviting low delivery into the box.

However, just as Northern Ireland appeared to have weathered the early storm, they fell further behind.

In the 22nd minute, Encarnacao found space on the left and delivered an excellent pass into Silva's path and her first-time finish crashed off the crossbar and over the line.

Portugal continued to show their quality and, five minutes later, extended their advantage after defender Holloway misjudged Amado's cross and deflected the ball into her own net.

It was a much more positive second half from the hosts, but Jackie Burns was forced to make a great save early on to deny Silva her second of the evening.

Amado was then dismissed as, after already being on a yellow for throwing the ball away, she fouled lively debutant Kess Elmore 10 minutes later and was dismissed.

After the red card, Northern Ireland's confidence grew with Mason's strike forcing Ines Pereira into a good save.

Playing with 10 did not stop Portugal from adding a fourth with Pinto's effort from 30 yards catching Burns out as it nestled in the corner.

Substitute Chambers added to the home side's misery when she was sent off for a clumsy hair pull on Correia in the box.

Northern Ireland manager McArdle described the play-off as an opportunity to write their own movie script, but the first leg at Inver proved to be a difficult opening scene.

The start of a movie normally sets the tone for what is to follow and Portugal made their intentions clear from the outset.

Northern Ireland showed glimpses of promise, but defensive lapses and the quality of their opponents in the first half proved decisive and they now take a commanding advantage.

The level of the opposition does have to be considered with Portugal a Nations League A side who also finished top of their World Cup qualifying group and lost just one game in the process.

This game will present plenty of learning points for the young panel available to McCardle, as 13 of the squad are 24 or under and their second-half performance was encouraging.

They also had chances of their own, but their quality in the final third continues to be a recurring problem.