In the first leg, AS Roma was quite advantaged because since the 85th minute Atletico only played with 10 men, so AS Roma was able to score another goal before the match really ended.
Meanwhile, the second match might be more difficult, because AS Roma will be visiting the opponent's headquarters. They can no longer hope that there will be luck that benefits them, Ranieri's team really has to fight even harder to be able to maintain their advantage in order to advance to the next round.
It's Athletic Bilbao, not Atletico Madrid.
Bilbao played very well at Olimpico stadium last week and they nearly left it with a draw, but the second yellow card and a red card made disadvantage in about last 10 minutes of the match. It's impressive that AS Roma attacked very intensively and well in those last minutes, by creating enough pressure and chances. The winning goal comes at very last second but it doesn't mean before that moment, Roma did not create any chance.
Even so, they managed to get a win in the first leg and the victory gave Roma a slight advantage to play much better in the second leg. The challenge in the second leg is indeed not easy because they will play at the opponent's home so the pressure will certainly be much greater. If they want to qualify for the next round, Roma must be able to make a difference because Athletic Bilbao themselves will definitely try to put pressure on them in the early minutes of the match.
Advantage is small and AS Roma can see how Liverpool was eliminated by PSG and Real Madrid had a very difficult match with Atletico Madrid after winning their first leg matches. Bilbao are strong and can do well like PSG and Atletico Madrid in Champions League, and this match can be decided by penalty shootouts too.
Roma only need a draw in Bilbao to move to quarter finals but this task is not easy by playing at Bilbao home stadium and a lot of pressure on the pitch and on stadium too. Ranieri with his experience can guide his players to keep their cold heads in this tough match, and if players fail to stay calm, they will have risk of losing this match in Bilbao.
Actually it was very obvious that Roma were going to face lots of problems playing against Athletic Bilbao who are at an extraordinary form at the moment as far as this tournament is concerned, right now in this tournament I can categorically state that they are one of the favorites alongside Manchester united and Real betis too, and if can remember vividly, you would notice that Spanish clubs often dominate this tournament and from the inception of this particular fixture between AS Roma and Athletic Bilbao, it was quite clear that Bilbao would go through and they didn't disappoint the home fans.