Graham Burke went from hero to villain for Shamrock Rovers as he scored, and then was sent off for violent conduct, as they were held to a 1-1 draw by St Patrick's Athletic in Tallaght Stadium.
The former Aston Villa striker had opened the scoring for the Hoops early in the first half before Christy Fagan equalised in spectacular fashion ten minutes after the break.
Both teams had chances to win the game but Rovers sacrificed any chance of climbing above Bray Wanderers into third when Burke was dismissed for a mindless kick on former Hoop Pat Cregg.
The game was typical derby fare to begin with as neither side was prepared to give too much away, and the first shot in anger came in the 11th minute, a tame effort curled wide by Pats' JJ Lunney.
Rory Feely had another chance to give the Saints the lead as he shrugged off Gary Shaw, who was dragging his shirt, to shoot inside the area but Tomer Chencinski was down quickly to save.
And Rovers just as quickly moved up the pitch, countering in numbers, and took the lead through a fine finish from Burke, his fifth of the season.
He capitalised on a mistake from Michael Barker, ignored the shouts of Brandon Miele to square it for a tap-in, and picked out the corner of the net himself.
Saints could have equalised almost immediately as Darragh Markey rode a couple of challenges wide on the right and teed up Lunney, but this time his shot was straight at the goalkeeper.
Rovers attacked with more vim and purpose with the cushion of a goal and could have doubled their lead had Shaw managed to get his head an extra few inches closer to Miele's cross from the right.
Pats keeper Conor O'Malley has assembled an impressive highlights reel already this season and he added to it with a fine double save from Burke and then Ryan Connolly after Cregg has been booked for a needless tug on Miele's shirt on the edge of the box.
And the Saints should have gone into the break on terms after Lee Desmond intercepted a hospital pass from Chencinski to Connolly and played in Fagan, but with just the keeper to beat he curled his shot badly wide.
Fagan did get his equaliser ten minutes into the second half as Rovers suffered another defensive malfunction and Lunney teed the striker up in plenty of space in the box and he finished emphatically, blasting the ball into the top corner to leave Chencinski helpless.
They very nearly completed the turnaround moments later as Fagan picked out Byrne's run from deep and the winger saw his shot across creep wide of the far post.
Burke was then sent off in farcical circumstances as he ran the ball out for a throw before swinging a wild boot behind Cregg's, missing the midfielder by millimetres.
He was shown a straight red card by referee Robert Hennessy, his second dismissal for the same offence this season, having also walked after scoring against Dundalk on the opening day.
Conan Byrne made an attempt to replicate his wondergoal at Dalymount Park by attempting to lob Chencinski from well inside his own half, but the Canadian keeper was live to it.