The midfielder had put Spurs ahead but they ended going down 2-1 to their London rivals, who they now trail by seven points in the Premier League.
Eriksen has found hitting the back of the net difficult this season so was pleased to get on the scoresheet, but disappointed it did not change the result.
"I've been unlucky with the keepers having good days or missing at the last moment," Eriksen told Tottenham's official website.
"I've been in good positions and it's just about taking the chance.
"I was in a good position and I took the chance and profited from it, but it takes away from the glory when we end up losing. It makes it a different, bitter feeling."