Dundee welcomed Forfar to Dens in the League Cup exactly a week after knocking them out of the Ramsdens Cup in extra time.
It was extra time required again and a little extra as Dundee found the winner 121 minutes and 50 seconds into the match.
Peter MacDonald who scored a free kick into the Shankly End last week stepped up again with a set piece and again found the top corner.
It was a match which Dundee dominated despite going behind and playing a large spell with a man less.
Forfar took the lead through an Ian Campbell penalty just before half time of regular time. Dundee leveled through Jim McAlister but Kevin McBride saw red midway through the second half for a second booking.
The referee leveled up the numbers in extra time when Stuart Malcolm was also given a second booking. Forfar had almost seen the match out to penalties but MacDonald free kick right at the death saw Dundee through to the next round.
