The Champions League quarter-final second legs are here, and the competition's two most recent winners must overcome first-leg deficits to reach the final four on Tuesday.

Defending champions Chelsea were downed by a stunning Karim Benzema hat-trick at home to Real Madrid, who are bidding to be crowned European champions for a 14th time.

Bayern Munich, meanwhile, suffered a shock reverse at Unai Emery's Villarreal, who will surely require a remarkable defensive performance to keep the free-scoring Bundesliga leaders at bay in Bavaria.

Here, Stats Perform unpacks the pick of the data from Tuesday's crucial European ties. 

Real Madrid v Chelsea: Benzema brilliance puts hosts in driving seat

Benzema's Stamford Bridge hat-trick has put Los Blancos on the brink of a semi-final spot, and he will be looking to continue his incredible European campaign when Chelsea try to overcome a 3-1 deficit in Spain.

After hitting consecutive European trebles, Benzema's tally of 11 goals is a new record for the most strikes by a French player in a single edition of the competition, and matches his record across the last two editions combined (he scored six goals in 2020-21 and five in 2019-20).

The 34-year-old's understanding with Vinicius Junior caused Chelsea all sorts of problems in London, and the duo have now assisted each other a combined five times in the Champions League this term (Vinicius providing four assists, Benzema one), the most of any two team-mates in the competition.

Carlo Ancelotti will qualify for the semi-finals for a record eighth time if Madrid can maintain their advantage against his former employers, equalling Pep Guardiola and Jose Mourinho.

Chelsea, meanwhile, are making their first trip to the Santiago Bernabeu in European competition, and must become the first English side to win a Champions League game there by more than one goal to have any chance of progressing.

Goalkeeper Edouard Mendy's costly mistake at Stamford Bridge has left the Blues on the brink of an exit, with his dire pass to Benzema representing his first error leading directly to a goal in 20 appearances in the competition.

Chelsea may be encouraged by the fact they have not lost both legs of a Champions League tie since going down to Bayern Munich in 2019-20's last 16, and have won three and drawn two of their last six meetings with Los Blancos.

However, with Madrid progressing from nine of their previous 10 ties after winning an away first leg (the exception being a 5-3 aggregate loss to Ajax in 2019), Chelsea look unlikely to revive their title defence.

Real Madrid in CL knockouts after winning first away leg

Bayern Munich v Villarreal: Emery eyes landmark success against Bavarian giants

Elsewhere, Bayern Munich are looking to avoid consecutive last-eight eliminations when they host Villarreal, with Arnaut Danjuma giving Unai Emery's men a precious 1-0 first-leg lead.

Danjuma has six Champions League goals this term, with only Robert Lewandowski (12), Benzema (11), and Mohamed Salah (eight) managing more, and could prove the visitors' best outlet on the counter-attack.

Indeed, Villarreal will certainly require a resolute defensive performance in Munich, having conceded 22 shots in their surprising home triumph.

However, Julian Nagelsmann's side were uncharacteristically wasteful in Spain, and their four shots on target last Wednesday marked the lowest such tally managed by a team to attempt over 20 shots in the competition this season.

Robert Lewandowski

Bayern unquestionably have what it takes to turn the contest around, however, and haven't gone consecutive Champions League games without scoring since a 5-0 aggregate loss to Real Madrid in 2013-14's semi-final tie.

Lewandowski will carry the burden of rescuing the Bavarian giants, having already scored two European hat-tricks in Munich this season (against Benfica and RB Salzburg). Only Cristiano Ronaldo (for Real Madrid in 2015-16) has ever managed three trebles in one Champions League campaign.

If the Yellow Submarine can pull off a remarkable success at the Allianz Arena, Emery will progress beyond the competition's quarter-finals for the first time in his career.

But the omens do not make for great reading for the Spaniard. The only previous time a side of his won an opening leg in the competition's knockout stages (Paris Saint-Germain's 4-0 win over Barcelona in 2017), they became the first team to be eliminated after winning a first leg by four goals, falling to an incredible 6-1 away loss.