Kepa Arizzabalaga saved two penalties, as Chelsea defeated Frankfurt 3-2 on penalties, to qualify for the Europa League final, where they face Premier League rivals Arsenal.
The game had ended 1-1 after 120 minutes of action at Stamford Bridge and 2-2 on aggregate.
The Gunners qualified for the final of the Europa League, following a thrilling 4-2 win over Valencia at the Mestalla on Thursday.
Kevin Gameiro struck first to give the LaLiga side the lead, before Pierre-Emerick Aubameyang levelled six minutes later.
Gameiro cancelled out Alexandre Lacazette’s instinctive strike in the second half, before Aubameyang’s brace settled the tie.
The final will be played in Baku on May 29.