If City win the two games, they will go top of the table.
The Gunners easily tore through Chelsea’s defence line, scoring 5 to set a new record against London rival.
Real defeated Manchester City 4-3 in the shootout.
Arsenal would have returned to the Premier League summit with a win but now sit second, two points behind reigning champions Manchester City.
Eberechi Eze’s 14th minute goal was all Palace needed to secure the maximum points.
The first leg of the heavyweight clash between Arsenal and Bayern Munich ended in a 2-2 draw at the Emirates Stadium.
Four minutes before the end of normal time, Leandro Trossard sealed the win for Arsenal from a launching pass by Havertz.
Odegaard opened the scoring for Arsenal in the 24th minute.
Arsenal dropped from top of the Premier League table to second place after the Gunners played out a goalless draw against Manchester City at the Etihad Stadium on Sunday
The English side beat the Portuguese giants in a penalty shootout after playing 1-1 on aggregate.
