Arsenal and Leverkusen staring down the barrel

After allowing the international calendar to take centre stage for a week, the UEFA Champions League returns on Tuesday. AC Milan and FC Barcelona look odds-on to reach the last eight, but the other two round of 16 ties are still up for grabsafter tight first legs.

SL Benfica v FC Zenit St Petersburg
A topsy-turvy opening instalment in Russia has left this tie in the balance. Benfica's two away goals – the second of which looked to have secured a late draw until Roman Shirokov's 88th-minute winner – should stand them in good stead back in Lisbon, where a record of 15 victories, three draws and just one defeat in their last 19 European home games will inspire confidence among Jorge Jesus's squad.

Zenit coach Luciano Spalletti, meanwhile, is without Danny – out for the season with a torn cruciate ligament – and cannot call upon recent loan signing Andrey Arshavin. Back in domestic action after more than three months out, the Russian Premier League leaders will hope Tuesday can inject further momentum into their season.

Arsenal FC v AC Milan
If Arsenal's European campaign is to continue, they must do what only three teams have ever done in the history of UEFA competition – overturn a four-goal first-leg deficit. Beaten 4-0 in Italy, Arsène Wenger's team must equal a UEFA Champions League comeback record held by Milan themselves, achieved in the 2003/04 quarter-finals.

The Rossoneri are unbeaten in two visits to Arsenal, but coach Massimiliano Allegri remains cautious. "I wish to underline that we have not qualified yet," he said. Wise words, though the fact Arsenal have prevailed only twice in UEFA competition ties after losing the first leg away is another portent in Milan's favour.

FC Barcelona v Bayer 04 Leverkusen
Leverkusen's is an unenviable task. Only 3-1 down they may be, but on the face of it the Bundesliga outfit look to be staring as starkly down the barrel as Arsenal. Holders Barcelona are unbeaten in 13 European home matches and eyeing up a fifth straight appearance in the last eight, while Leverkusen are without an away victory in the UEFA Champions League in a decade.

Back on song in the Spanish Liga, Josep Guardiola's charges seem to have recovered from that smallest of wobbles they suffered during the early part of this year.

APOEL FC v Olympique Lyonnais
APOEL made history by becoming the first Cypriot side to reach the knockout phase but will need to overturn a 1-0 first-leg loss if their fairy-tale campaign is to continue. APOEL, though, are tough nuts to crack in Nicosia and went nine European home games undefeated before losing 2-0 to FC Shakhtar Donetsk on matchday six.

Lyon enjoyed a far better time of it in their last group match, triumphing 7-1 at GNK Dinamo Zagreb, and have the experience of eight successive round of 16 appearances behind them. The last word, however, goes to APOEL's William Boaventura: "We always tend to struggle away then we win at home." Rémi Garde's men have been warned.

The final round of 16 second legs will be played on 13 and 14 March:

FC Internazionale Milano v Olympique de Marseille
FC Bayern München v FC Basel 1893
Chelsea FC v SSC Napoli
Real Madrid CF v PFC CSKA Moskva