GLASGOW, Dec 26 (Reuters) - Celtic returned to the top of the Scottish Premier League with a 2-0 win at Dundee United thanks to second half goals from Jan Vennegoor of Hesselink and Stephen McManus. They had surrendered first place for an hour after city rivals Rangers beat Motherwell 3-1 earlier on Wednesday. Celtic moved to 40 points from 19 games with Rangers on 38 from 17. Dutch striker Vennegoor of Hesselink headed home a corner from Paul Hartley from six metres in the 68th minute and defender McManus bundled in the second goal six minutes later following a Hartley free kick into the penalty area. At Rangers, French striker Daniel Cousin put the home side in front four minutes from the interval with a 15-metre shot following a cut-back by defender Steven Whittaker. Motherwell levelled with a Paul Quinn header from six metres on 64 minutes after a corner by Ross McCormack to the back post. Six minutes later Rangers went 2-1 ahead when a Charlie Adam cross was deflected into his own net by Motherwell defender Jim Paterson. Substitute striker Kris Boyd rammed home the third in stoppage time to secure the win and take Rangers top on 38 points from 17 games. St Mirren won 1-0 at Hearts with a first half goal from Stephen McGinn. Kilmarnock beat Hibernian 2-1 and bottom club Gretna rescued a point in a 1-1 draw with Aberdeen courtesy of a stoppage time equaliser from sub Allan Jenkins while Falkirk won 1-0 at home to Inverness Caledonian Thistle.