The second derby game of the season between the North-West rivals ended in a 2-2 draw at the Brandywell last night.
Ryan Curran headed the opening goal in the 20th minute for Harps.
Rory Patterson should have equalised in the 29th minute when he was one on one with the keeper, but he lifted the ball wide of the goal and the advancing keeper.
Josh Daniels drew Derry level on 84 minutes with a side foot finish three yards out.
Rory Patterson made up for the earlier miss with a strong shot from the left edge of the box two minutes from the end.
Harps got their deserved equaliser in the 90th minute when former Derry player Sean Houston headed in past a stunned Derry keeper.