Definition of "extra-time"

Who was the first England player to force a save out of the West German goalkeeper in the first period of extra-time in the 1966 World Cup final?

2011, Adam Pearson, The England Quiz Book, page 1990

The match would go to extra-time.

2014, Tom Oldfield, Arsene Wenger - The Unauthorised Biography of Le Professeur

The game started to slow toward the end of extra-time and I can honestly say those were the first moments when my thoughts started to wander to the prospect of a penalty shoot-out.

2015, Packie Bonner, The Last Line: My Autobiography