On Thursday night, the crucial second legs of the Europa League quarter-final take place. Two of the Premier League’s top six head into their quarter-final ties with leads. Here is what is happening on a big night of action in Europe’s secondary competition:

Chelsea v Slavia Prague (Kick-off 8 PM)

Chelsea takes a slender lead 1-0 goal lead into their second leg clash with Slavia Prague at Stamford Bridge. A late Marcos Alonso goal in the Czech Republic in the first leg was enough to give the Blues a lead and an away goal.

The victory gives Maurizio Sarri’s side a cushion going into a potentially tricky clash. However, the Blues have a good recent record in the Europa League, having recorded 13 victories in their last 14 games in the competition.

The fact that the team from south west London has kept clean sheets in six of their last eight matches in the competition has been a big factor in that good recent European run. Chelsea are favourites to win this tie and the competition.

The first leg defeat by Chelsea, ended a five-game unbeaten run in the Europa League for Slavia, win which they had recorded three wins and two draws. The Czech outfit has been prolific of late in the Europa League, scoring at least two goals in three of their of last four European outings.

Slavia has an unconvincing recent away record in the Europa League. However, a record of three wins in their last 20 games on their travels in the competition is not a great one.

Napoli v Arsenal (Kick-off 8 PM)

Arsenal travel to Naples to face Napoli with one foot in the semi-finals after a 2-0 victory at the Emirates Stadium in the first leg last week.

Napoli’s recent form has been inconsistent of late in all competitions. In fact, the home side has won four and lost two of their last six matches in the Europa League, which illustrates their inconsistency.

The two defeats were in their last two European outings at Salzburg and in north London in the reverse fixture. Carlo Ancelotti’s team conceded at least two goals in both defeats.

Napoli are tough nuts to crack on home soil, as they have suffered just one defeat at the San Paolo in 16 outings in the Europa League. The Italian side has also won their last two home games in the competition without conceding.

Arsenal have been on a decent run of form of late, claiming wins in five of their last six outings in all competitions, while conceding just once in the process. The Gunners have won three of their last four European games, scoring at least twice and keeping three clean sheets in the victories.

It is not all positive for Unai Emery’s team heading into this clash, as they have suffered defeat in their last two Europa League games against BATE and Rennes. They have also won just three times in their last 13 matches on their travels in all competitions.

Thursday nights other Europa League quarter-final second legs (Kick-off 8 PM)

Eintracht Frankfurt v Benfica (2-4 aggregate)

Valencia v Villarreal (3-1)

Who will make it to the Europa League semi-finals?