The goal was Wikheim's first for Djurgården.
A goal that was created after the Norwegian won the ball in midfield.
The performance was by Emmanuel Banda, who was also substituted three minutes earlier.
Hammarby chased the equalizer - and they came close.
With five minutes left of extra time, Astrit Selmani dotted the crossbar with his forehead, and a moment later in the forcing phase, Björn Paulsen did the same.
But there was no 1-1, and Djurgården goes up in the league lead with the victory.
For Bajen, it is all the more difficult, as they now have a win in the last seven Allsvenskan matches.
The article is updated.