Arsenal v AC Milan
No side in Champions League history have ever come back from four goals down after the 1st leg of a knockout round. The last side to do this in European competition was Real Madrid in 1985 against Borussia Mönchengladbach (1-5 A, 4-0 H).Milan exited the Champions League in 2003/04 at the quarter-final stage despite beating Deportivo 4-1 in the 1st leg, losing the 2nd leg 4-0 - the only side in Champions League history to be eliminated in a knockout round after winning the 1st leg with a three-goal difference.
The 4-0 defeat in the 1st leg was Arsenal's heaviest defeat ever in European competition.
In seven two-legged ties and one final (excluding the Super Cup), no Italian side has ever eliminated Arsenal in a knockout competition.
In each of the previous five meetings between Arsenal and AC Milan (incl. European Super Cup), at least one has team failed to score. Both previous meetings in London have ended goalless.
Milan have been knocked out by English clubs in the Last-16 stage of their last three Champions League participations and have failed to score in five of the six matches played in those ties.
Milan are unbeaten in their last five Champions League away matches, drawing the last four.
Arsenal are unbeaten in their last 12 Champions League home games, winning 10 of them.
Arsenal have lost their last two Champions League games, but they have never lost three games in a row in the history of this competition.
Arsenal boast the highest shooting accuracy percentage in the 2011/12 Champions League, with 64% of their attempts on target.
Of all 16 sides that reached the knockout stages, only APOEL (39) have attempted fewer shots than Arsenal (64, incl. blocked).
Zlatan Ibrahimovic has found the net in all of his five Champions League appearances this season. He scored a brace in his only club visit to the Emirates, with Barcelona in March 2010.
Benfica - Zenit St Petersburg
Zenit St Petersburg are the first Russian club from a city other than Moscow to reach the knockout stage of the Champions League.Zenit are unbeaten in six Champions League games, thus equaling the Russian record set by Spartak Moscow in 1995/96.
Benfica have won just one of their last four Champions League games, a 1-0 home victory over Romanian side Galati.
The Portuguese side are unbeaten in seven home games in Europe (excluding qualifiers), winning five of them.
Zenit have failed to win any of their last four Champions League away games (two draws, two defeats), but secured a goalless draw at Portuguese side Porto FC in the group stage.
Benfica have scored at least one goal in each of their 11 games in Europe this season (including qualifiers).
The Lisbon side have scored the opening goal in each of their seven Champions League games this season.
Benfica have committed more fouls than any other side in this Champions League (113).
Zenit have won three and drawn one of their four games against Portuguese opposition in Europe, including taking four points against Porto in this season's group stage.
Zenit's Portuguese winger Danny has created more chances for team mates than any other player in the Champions League this season (21).
Benfica's Nicolas Gaitán has delivered the most assists in the 2011/12 Champions League (five).
Barcelona - Bayer Leverkusen
These sides have met on seven occasions in European competition, with Barcelona winning the last four encounters.Only two teams in Champions League history have reached the next round after losing the 1st leg of a knockout round at home (Ajax in 1995/96 and Internazionale last season).
The Blaugrana have allowed their opponents just 11 shots on target in this season's competition, less than any other team.
Bayer have scored four headed goals this Champions League season, more than any other team.
Barcelona have dominated possession in all of their 45 Champions League matches under Pep Guardiola's management.
The Blaugrana have scored in each of their last 28 Champions League games (70 goals in total).
Leverkusen are without a win in their last 11 away games in the Champions League, losing eight of these. Their last win was a 2-0 victory at Maccabi Haifa back in October 2002.
Barcelona are unbeaten in their last 13 Champions League games, winning 11 of them.
Leverkusen have only kept six clean sheets in their last 43 Champions League matches.
Barcelona have recorded the highest ball possession percentage (74%) and the highest passing accuracy (91%) in this season's competition.
Starting with his goal in the 2009 final, Lionel Messi has scored 28 goals in his last 29 Champions League starts, including seven in six this season.
Liverpool were the last side to dump Barcelona out at the last 16 stage of the Champions League, back in the 2006/07 season.
APOEL - Lyon
This is the first appearance by a Cypriot club in the knockout stage of the Champions League.APOEL have picked up more cards (21 yellows) than any other side in this Champions League season.
The Cypriot champions have allowed their opponents more shots on target against them (48) than any of the other teams who made the Last 16.
They also had fewer shots than any other Champions League side this season (39, including blocked).
Lyon are unbeaten in their last three Champions League matches, winning the last two.
APOEL have failed to score in each of their last three Champions League games.
Lyon have failed to win each of their last eight away games in the knockout stages of the Champions League, losing six of them (including the last three).
Lyon have failed to score in five of their last eight Champions League matches.
APOEL have lost each of their three previous games against French opposition in Europe (two defeats v PSG in the 1993/94 Cup Winners' Cup prior to the 1st leg of this Champions League).
Five of APOEL's six Champions League goals this season have been scored by Brazilians AÃlton Almeida (three) and Gustavo Manduca (two).
Bafetimbi Gomis has scored 50% of Lyon's Champions League goals this term (five out of 10).
