A bizarre long-range own goal helped Nottingham Forest earn a hard-fought 1-1 draw at Porto in the first leg of their Europa League quarter-final.
Forest fell behind early when William Gomes tapped home at the far post as the home side made a fast-paced start at the Dragao, but that lead lasted just two minutes.
There appeared to be little danger when Martim Fernandes gained possession midway inside his own half, but without looking, the Porto defender attempted a back pass to his goalkeeper Diogo Costa.
However, the young Portuguese got too much on the pass as it zipped past a stranded Costa, hovering on the edge of his box, and that changed the momentum of the game as Forest managed to then largely frustrate their opponents to hold the advantage at the halfway point of the tie.
Forest boss Vitor Pereira, who was honoured prior to kick-off having won back-to-back Portuguese titles while in charge of Porto between 2011-13, rung the changes with a crucial Premier League game at home to Aston Villa on Sunday.
That meant a first start after a nine-month layoff for striker Chris Wood, who scored 20 goals last season, but had not played for Forest since Ange Postecoglou's final game in October.
There was also a change in shape by the visitors, who went to three at the back, although they were all at sea as Porto took an 11th-minute lead following a well-worked move, before Fernandes's memorable own goal soon brought them level.
The home side, who have been in impressive form both domestically and in Europe since losing 2-0 at Forest in the league phase earlier this season, largely controlled proceedings thereafter.
However, the closest they came to retaking the lead was when Stefan Ortega kept out Gomes' well-struck shot with 20 minutes to go, before substitute Victor Froholdt - set up by Pepe's gorgeous defence-splitting pass - was inches away from finding the far corner late on.
Forest, in their first European quarter-final since losing in the Uefa Cup to Bayern Munch 30 years ago, held on though and may even have won it had Igor Jesus's effort not be ruled out by the Video Assistant Referee for a foul on Costa midway through the second half.
Either way, they must now fancy their chances of going one better under the City Ground lights next Thursday and set up a potential all-English semi-final with Villa.
Nottingham Forest head coach Vitor Pereira on TNT Sports:
"A good result in my opinion. To face two competitions we need to play with everyone. The players that started today did good work. In the end, 1-1, the game is open to play at home and decide qualification.
"Porto playing at home are a strong team. They have momentum with supporters. At Forest I try to balance the two competitions, it was very clear we played with nine different players to the last game. I think we did well. The players tried everything.
"The first two subs we did I was thinking about the next game against Villa. It's very important for us to get points in the league and this is the only way."
