Inter Milan advanced to their first Champions League quarter-final in over a decade after holding out for a 1-0 aggregate victory against Porto.
Simone Inzaghi's side, who were 1-0 winners in the first leg at San Siro three weeks ago, saw out a hard-earned goalless draw at Estadio do Dragao to take them through.
The Nerazzurri subsequently secured their first last-eight appearance in Europe’s premier club competition since the 2010-11 season.
Despite a flurry of late chances, Porto — who had Pepe sent off for a second yellow card in stoppage time — were unable to convert it into the goals they required to reach a third quarter-final in five years.
Trailing 1-0 from the first leg, Porto almost levelled the tie in spectacular fashion after three minutes, Andre Onana forced to scramble across and tip away Mateus Uribe's 30-yard effort.
At the other end, Diogo Costa produced a smart reflex save to thwart Edin Dzeko following a quickfire Inter counter.
Porto turned up the pressure towards the end of the half. Federico Dimarco's brilliantly timed last-ditch intervention denied Evanilson a clear sight on goal, while Stephen Eustaquio was inches away from connecting with Pepe's inviting cross.
Uribe and Barella were off target with long-range strikes early in the second half, which provided few clear opportunities for either side.
Porto, who had won each of their four previous four home matches against Italian opponents, controlled possession as they desperately sought to square the tie.
The hosts launched a last-gasp surge in stoppage time and Denzel Dumfries blocked Ivan Marcano's shot on the line, while Mehdi Taremi and Grujic both struck the woodwork before Pepe's dismissal as a remarkably stubborn Inter held on.
What does it mean? Defensive heroics see Inter through
Despite enjoying just 32 per cent of possession and registering four shots to their opponents’ 21, Inter held their nerve to seal a last-eight berth.
The Nerazzurri have progressed from five out of six two-legged Champions League knockout ties when winning the first leg.
As for Porto, they have now been eliminated on seven of the eight such occasions when they have lost the opening leg.
Onana and co keep out Porto
You must go back to their 2009-10 quarter-final against CSKA Moscow for the last time Inter progressed from a Champions League knockout tie without conceding across both legs. Ironically, they went on to lift the trophy that year.
It was some effort from the Nerazzurri to repeat the feat nearly 13 years later. Onana did his bit between the sticks as he made six saves, while Alessandro Bastoni and Francesco Acerbi both chipped in with a game-high five clearances each.
Dzeko drought goes on
The veteran striker has now gone 10 matches without scoring for Inter since netting in their Supercoppa Italiana win over rivals Milan in January 18.
Although his side were defending their lead throughout the second leg, he mustered just a single shot on goal before he was substituted for Romelu Lukaku with 20 minutes remaining, having registered the second fewest touches (32) and passes (19) among any starting player for the visitors.
Key Opta Facts
Porto have now been eliminated from seven of their eight two-leggedChampions League knockout ties after losing the first leg, only progressing from this position in 2018-19 against Roma.
Inter have booked their place in the quarter-finals of the Champions League for the seventh time overall and for the first time since 2010-11 when they were knocked out in the last eight by Schalke.
Porto have won just two of their last seven Champions League knockout games on home soil, drawing one and losing four.
Inter have kept three consecutive clean sheets in Champions League knockout games for the first time since April 2010.
What's next?
The big games keep on coming for Inter. Just the small matter of the Derby d'Italia against Juventus awaits them on Sunday while, on the same day, Porto look to respond when they travel to Sporting Braga.
