Manchester United come up against a Barcelona side with a formidable home record on Tuesday, with the Premier League club aiming to overturn a one-goal deficit from the first leg and book a spot in the Champions League semi-finals.
Barcelona have not been beaten in 30 Champions League games at Camp Nou and will be confident of maintaining that streak against United, particularly given Lionel Messi's history against English clubs in the competition.
In Tuesday's other quarter-final second leg, Ajax travel to Juventus with their tie delicately poised after an absorbing 1-1 draw in Amsterdam last week.
Here are some essential Opta facts as we get ever closer to finding out who will progress to the last four.
Barcelona v Manchester United
4 - Of the 70 previous occasions a side has won a Champions League knockout tie first leg away from home, just four have been eliminated (six per cent). However, two of those instances have been in this season’s competition, including once by Manchester United.
39 - Barcelona have progressed from 39 of their 41 European ties in which they won the first leg away from home - the exceptions were against Cologne in the 1980-81 UEFA Cup and against Metz in the 1984-85 Cup Winners’ Cup.
30 - Barcelona are unbeaten in 30 Champions League home games, the longest such run in the competition (W27 D3). They've also not conceded more than once in any of those 30 games (15 goals in total) since a 3-0 loss to Bayern Munich in the 2012-13 semi-finals.
90 - Ninety per cent of Manchester United's Champions League goals this season have come away from home. However, the Red Devils have won just one of their last five away knockout stage games in the competition (D2 L2).
0 - In their first leg defeat, Manchester United failed to register a single shot on target for the first time in a Champions League game since March 2005 (0-1 v AC Milan).
22 - Barcelona's Lionel Messi has scored 22 goals in 31 Champions League games against English opponents, more than any other player in the competition. Thirteen of those strikes have come in his last nine appearances against English sides at Camp Nou, including hat-tricks v Arsenal (April 2010) and Manchester City (October 2016).
Juventus v Ajax
10 - Juventus are unbeaten in their last 10 meetings with Ajax in all competitions, the joint-longest such run for one side against another in European matches (also Bayern Munich v Benfica).
2 - Ajax have been eliminated on two of the three previous occasions they have drawn the first leg of a Champions League knockout tie at home, most recently in the 2005-06 last 16 against Inter Milan.
2 - Juventus have lost two of their last five Champions League home games, as many as they had in their previous 45 in Turin in the competition (W28 D15 L2).
8 - Juventus striker Cristiano Ronaldo has scored in his last five Champions League games against Ajax, netting eight goals in total. The Portuguese forward has also scored 51 per cent of his total goals in the competition in the knockout stages (64/125).
2 - Ajax have won their last two Champions League away games, last winning more consecutively in the competition between November 1995 and March 1997 (seven).
53 - Dusan Tadic has been directly involved in 53 per cent of Ajax's 17 Champions League goals this season (six goals, three assists). The last player to score more than the Serbia international for Ajax in a single Champions League campaign was Jari Litmanen in 1995-96 (nine).