James Keatings scored the only goal of the game as Hearts stretched their lead at the top of the Scottish Championship to 15 points courtesy of a 1-0 win at Livingston.A thumping 4-0 victory for bitter rivals Hibernian is rarely something to be celebrated but the fact it came against second-placed Rangers will have raised the spirits of Hearts' army of fans travelling to the Energy Assets Arena.Around 7,500 supporters made the trip and they were on their feet in the 14th minute when Jason Holt was fouled in the box, only to see Keatings' penalty saved by Darren Jamieson.That miss may have knocked the confidence of most players but Keatings had opened the scoring in the previous three games and ensured he did so again as he finished Billy King's low cross at the back post after 25 minutes.Livingston improved after the break but could not find a breakthrough and Hearts finished strongly to make it seven league wins in a row.