GLASGOW, Jan 28 (Reuters) - Leaders Celtic were held to a 3-3 home draw by Dundee United in a Scottish Premier League thriller on Saturday.
Elsewhere, Paul Hartley struck twice as Hearts hammered third-placed Hibernian 4-1 in the Edinburgh derby.
Celtic top the table with 58 points from 24 games while Hearts, in second spot, have 50 from the same number of matches.
Champions Rangers, 18 points behind the leaders in fourth position, play at Inverness Caledonian Thistle on Sunday.
Wales striker John Hartson headed Celtic in front from an eighth-minute free kick by Japanese midfielder Shunsuke Nakamura before United levelled with a low shot by Spaniard David Fernandez five minutes from the break.
Pole Maciej Zurawski nodded Celtic 2-1 ahead from Shaun Maloney's cross and Bulgarian Stilian Petrov marked the signing of a new contract that will keep him at the club until 2009 by firing in a 25-metre shot with the help of a deflection.
Lee Miller pulled a goal back for United before former Celtic striker Fernandez converted an easy chance to equalise.
"At 3-1 up I really did believe the game was finished," Celtic manager Gordon Strachan told BBC Radio Scotland.
"We were making chances at that time and had enough to score a couple more. I have to live with that disappointment for a couple of days until we get ready to play Motherwell in Wednesday's League Cup semi-finals."
Hartley's two goals for Hearts, one a penalty, came in the first half against Hibernian before Czech Republic striker Rudi Skacel made it 3-0.
Hibs had Gary Smith sent off before halftime following an off the ball incident.
Hearts made it 4-0 through Calum Elliot while Garry O'Connor netted a late consolation for Hibs.
In Saturday's other games, Aberdeen were held 2-2 at home by Kilmarnock, Dunfermline Athletic drew 1-1 with Motherwell and Falkirk won 1-0 at bottom team Livingston.