They are calling it the most open Champions League in years with traditional powerhouses Real Madrid and Barcelona no longer the all-conquering forces of old and contenders like PSG and Manchester City growing stronger every year.
Only one of the ties needs more than a two-goal swing from the first leg which means plenty of tension and excitement in the air as Messi, Ronaldo, Mbappe, Aguero, Kane, Modric, Griezmann and the rest do battle.
Sportsmail assesses the state of play for each tie in the last-16.
Real Madrid have won the last three Champions League tournaments… will they make it four?
BORUSSIA DORTMUND V TOTTENHAM – Tuesday March 5, 8pm
First leg score: Tottenham 3-0 Borussia Dortmund
The Champions League is the last realistic opportunity for Mauricio Pochettino to grab that elusive first trophy and his team sent out a major statement in the first leg, their comprehensive win at Wembley achieved without Harry Kane.
Kane is back for the second leg in Germany with both sides struggling for form. Tottenham have picked up only one point from nine in the Premier League but Dortmund are also shaky. The long-time Bundesliga leaders lost at Augsburg on Friday to allow Bayern Munich to join them level on points.
Spurs will be without Eric Dier, Harry Winks, Dele Alli and Kieran Trippier. Dortmund need teenage English winger Jadon Sancho to have more of an impact than he did at Wembley.
Key man: Marco Reus (Dortmund) – Captain and playmaker
If Borrusia Dortmund beat Tottenham, Marco Reus will likely be central to the comeback
REAL MADRID V AJAX – Tuesday March 5, 8pm
First leg score: Ajax 1-2 Real Madrid
Real have won the last three Champions Leagues and whatever problems they have domestically – and there are plenty – they aren’t going to give up their European crown without a fight. It will be a major surprise if they don’t complete the job over Ajax after Marco Asensio’s late winner in Amsterdam.
The big talking point in Madrid is the treatment being dished out by their fans to Gareth Bale, who scored one of the greatest Champions League goals in history against Liverpool last May but was jeered at the Bernabeu last weekend when Real were beaten by Barcelona in El Clasico.
Ajax’s best hope is that Real miss suspended captain Sergio Ramos at the back. They are second in the Dutch League behind PSV but are the highest scorers in Eredivise with former Southampton man Dusan Tadic contributing 16. Defender Matthijs de Ligt has been heavily linked with Barcelona.
Key man: Luka Modric (Real Madrid) – Current world player of the year
With captain Sergio Ramos suspended, Luka Modric has a vital role for Real Madrid
PORTO V ROMA – Wednesday March 6, 8pm
First leg score: Porto 1-2 Roma
Whoever gets through this tie will be regarded as the outsiders in the quarter-finals. With both teams of a similar standard, this could be one of the most exciting second legs. Roma have the slightest of leads thanks to a double from teenager Nicolo Zaniolo, regarded as the best Italian prospect since Francesco Totti.
Roma are a place outside the Champions League spots in Serie A and were humbled 3-0 by Lazio in the Rome derby at the weekend when ex-Manchester City defender Aleksandr Kolarov was sent off. But they have a good record in Europe and reached the Champions League semi-finals against Liverpool last season.
Porto will also be hurting after a 2-1 home defeat against main title rivals Benfica on Saturday but will be boosted by news that key Roma defender Kostas Manolas is a doubt because of an ankle injury and illness. Porto striker Adrian could start having scored their goal in the first leg as a sub.
Key man: Edin Dzeko (Roma) – Vast experience up front
Edin Dzeko is pivotal for last season’s Champions League semi-finalists Roma
PARIS SAINT-GERMAIN V MANCHESTER UNITED – Wednesday March 6, 8pm
First leg score: Manchester United 0-2 Paris Saint-Germain
If Manchester United can overturn a two-goal deficit in Paris, it’ll be a comeback to rank alongside the 1999 Champions League final win against Bayern Munich when current interim manager Ole Gunnar Solskjaer scored their winning goal. The home leg at Old Trafford remains Solskjaer’s only defeat in charge, his plans disrupted by injuries to Anthony Martial and Jesse Lingard as Kylian Mbappe scored for PSG.
United have been unstoppable on the home front so their confidence should be high particularly with Romelu Lukaku having netted four times in his last two games. PSG lead the French League by hefty 17 points with Mbappe on target twice in a 2-1 win at Caen on Saturday.
Before the tie, much was made of a foot injury to Neymar. But he wasn’t missed in the first leg while United’s talisman Paul Pogba is suspended for the second leg. Neymar and Edinson Cavani (hip) are unlikely to feature in Paris but United have an even equally damaging injury list with Alexis Sanchez and Martial likely to be out. Nemanja Matic, Ander Herrera and Lingard also missed the weekend win against Southampton.
Key man: Kylian Mbappe (PSG) – Unplayable at his best
If Manchester United can stop Kylian Mbappe, they may be able to defeat Paris Saint-Germain
JUVENTUS V ATLETICO MADRID –Tuesday March 12, 8pm
First leg score: Atletico Madrid 2-0 Juventus
Cristiano Ronaldo is set to be the biggest casualty of the last-16 unless Juventus can pull off a dramatic victory having been sunk in Spain by late goals from Jose Gimenez and Diego Godin. Ronaldo was primarily signed from Real Madrid to earn Juve their first Champions League since 1996 but it looks a tall order now.
Atletico have the incentive of knowing this year’s final is at their own stadium, the Wanda Metropolitano. Diego Simeone’s side are the last team you’d want to score two or more goals against – they have conceded only 17 times in 26 La Liga matches this season, the best record in Spain.
Juventus do have firepower – Paulo Dybala and Mario Mandzukic besides Ronaldo – and can rest players against Udinese this Friday, having beaten Napoli last weekend to go 16 points clear at the top of Serie A
Key man: Cristiano Ronaldo (Juventus) – Five-time Champions League winner
Cristiano Ronaldo has work to do if Juventus are to remain in the Champions League
MANCHESTER CITY V SCHALKE – Tuesday March 12, 8pm
First leg score: Schalke 2-3 Manchester City
Having won the first leg in Germany, this shouldn’t be the toughest test for Pep Guardiola’s Manchester City as they chase an unprecedented Quadruple – but the perfectionist manager will remind his players they trailed 2-1 in Germany going into the last five minutes.
There couldn’t be a greater contrast in current form between the two teams. City have clawed their way above Liverpool at the top of the Premier League after an eight-match unbeaten run in all competitions. Goalkeeper Ederson hasn’t conceded in his three games since the first leg at Schalke.
Schalke have won only once in their last eight games and were thumped 4-0 at home by Fortuna Dusseldorf at the weekend, a result that leaves them 14th of 18 teams in the Bundesliga.
While Guardiola has had to do without Aymeric Laporte, Fernandinho and Benjamin Mendy in recent games, his problems are minimal compared to Schalke, whose angry fans forced captain Benjamin Stambouli to hand over his armband after their latest loss.
Key man: Sergio Aguero (Manchester City) – Club record goalscorer
Sergio Aguero is key to Manchester City’s aims for an unprecedented quadruple
BARCELONA V LYON – Wednesday March 13, 8pm
First leg score: Lyon 0-0 Barcelona
This is supposedly not one of Barcelona’s greatest teams but they are seven points clear at the top of La Liga after beating Real Madrid at the weekend and are handily placed to reach the quarter-finals of the Champions League, a compeitition they haven’t won since 2015 due to Real’s dominance.
Despite being held in France in the first leg, the form of Lionel Messi will give them every confidence of progressing. The Argentine has scored 33 goals in 34 appearances this season and already has one Champions League hat-trick under his belt, against PSV in the group stages.
Lyon are third in the French League and showed when beating Manchester City at The Etihad they are capable of causing an upset. Their star man is French World Cup winner Nabil Fekir, once courted by Liverpool. Barca have injury doubts over Samuel Umtiti, Rafinha and Thomas Vermaelen
Key man: Lionel Messi (Barcelona) – who else?
Lionel Messi fired a blank in the first leg against Lyon – can the French side deny him again?
BAYERN MUNICH V LIVERPOOL – Wednesday March 13, 8pm
First leg score: Liverpool 0-0 Bayern Munich
Will it be a blessing in disguise for Liverpool to go out of the Champions League? You won’t hear it from Jurgen Klopp and history gives them a chance of going through. In 1981, Liverpool drew the first leg of their European Cup semi-final 0-0 at Anfield but went to Munich and drew 1-1 to advance on away goals, then beating Real Madrid in the final.
Klopp’s heavy metal football has gone a bit middle-of-the-road recently; the home tie with Bayern was the first of three goalless draws in four games. Roberto Firmino hasn’t scored in his last six games, Mohamed Salah for four – a drought by his standards.
Bayern are on a roll having won their last 13 games domestically. Robert Lewandowski’s double in a 5-1 win at Borussia Monchengladbach at the weekend took his season’s tally to 27.
Key man: Mohamed Salah (Liverpool) – Klopp needs his inspiration
Liverpool need Mohamed Salah to rediscover his scoring form for Bayern Munich