Gudmundsson played the entire match for Leeds but left Wembley and London on the losing side.
The match-winner for Chelsea was Enzo Fernández. In the 23rd minute, the Argentine headed in the only goal of the semi-final. The goal came after Leeds' Pascal Struijk was careless and lost the ball inside his own half.
Chelsea are chasing their first FA Cup title since 2018. The London club reached three straight finals from 2020 to 2022, but lost all of them.
The final on May 16 at Wembley awaits Manchester City, who beat Southampton 2-1 on Saturday.
