Inter Milan reached the Champions League quarterfinals for the first time in more than a decade after surviving a late barrage of pressure at Porto to escape with a 0-0 draw which took them through 1-0 on aggregate on Tuesday.
It was a disappointing night for the home fans at a sold-out Dragao stadium as the Portuguese champions tried in vain to wipe out the narrow deficit from the first leg in Italy.
A disciplined Inter side seemed content to hold onto their lead and did not face a serious threat until added time.
Then Ivan Marcano's effort was blocked on the goal-line by Denzel Dumfries and headers from Mehdi Taremi and Marko Grujic hit the post and bar, respectively, as Porto finally came alive.
Defender Pepe was then sent off for a second yellow card and Inter joined city rivals AC Milan in the quarterfinal draw, the first time they have reached the last eight since 2006.
With Napoli playing on Wednesday in their second leg at home against Eintracht Frankfurt with a 2-0 advantage earned in Germany, Italy could also have three teams in the Champions League quarters for the first time since 2006.
"We played an excellent game, the group stayed compact and played a great match. Excellent first half. In the last part of the match we all suffered together -- honour to this group", Inter coach Simone Inzaghi told Mediaset.
"In football, luck matters relatively. In the two-legged match we deserved to advance. Now we will play the quarterfinals with a lot of confidence."
After earning a hard-fought win in the first leg against a Porto side who went to Italy with an ultra-defensive gameplan, Inzaghi took a careful approach that paid off as his players preserved the lead with a steadfast display.
They waited for their hosts to show their hand, but Porto never really hit their stride until it was too late.
Not until late on, when coach Sergio Conceicao brought on Toni Martinez and Danny Namaso to make it three up front, did Porto throw everything at Inter in a move that almost worked in stoppage time when they were thwarted by the woodwork.