I do not see a clear favorite in the Manchester Utd - Atletico Madrid game. Both teams seem to be in quite good shape. Atletico wins matches in their league regularly. Manchester took a important victory over Tottenham last weekend. This result and the attitude of Cristiano Ronaldo, who scored 3 goals in this game, will certainly have a positive effect on the morale of the team. In today's match I will bet on the promotion of Manchester, mainly because they are playing the rematch at their stadium. However, I do not rule out extra time in this match.
Man Utd vs Atletico should pretty much be an even game and it's not easy to pick a side, both teams are consistent. Atletico Madrid who happened to be a very defensive team have been really poor defensively, so it gives Man Utd a bit of an advantage and Ronaldo would be really important for them tonight, these are the kind of matches he thrives on, provided the Man Utd supply line is functional.
I'd take Man Utd for a 2-1 win.
Ajax vs Benfica would be a more interesting matchup imo, as I expect a really attacking football and Ajax have been superb this season but they blew a 2-goals advantage in the first leg and I wouldn't expect them to have a similar game to day.. 3-1 win for Ajax is my prediction.