Manager Maurizio Sarri admits Chelsea made life difficult for themselves in reaching the semi-finals of the Europa League with a seesawing 4-3 victory over Slavia Prague and 5-3 aggregate triumph

With Chelsea leading 1-0 from the first leg, the tie should have been over as a contest after only 15 minutes as they thrice sliced Slavia apart.

But the Londoners faced some hairy moments as the visitors hit back twice to trail by just one on the night.

Sarri says they need a solution to their poor second halves as it is becoming a major issue.

Arsenal has joined their London rivals in the last four, with a 2-nil win at Napoli for a 3-nil aggregate win.