Dundee United beat Ayr United 2-1 at Tannadice on Tuesday night to move to within a point of promotion rivals Falkirk and Morton.
Simon Murray gave the IRN-BRU Cup winners the lead midway through the first half but Gary Harkins equalised from the penalty spot shortly after the interval.
Defender Mark Durnan claimed the decisive goal from close range 12 minutes from time to leave Ayr ninth in the table while United stay fourth.
In the night's other game, Albion Rovers beat East Fife 1-0 at the Exsel Group Stadium in Ladbrokes League 1 to climb to seventh place. Ryan Wallace scored the only goal 10 minutes into the second half.
Meanwhile, Championship leaders Hibernian have the chance to open up a 13-point lead at the top when they host Morton on Wednesday evening.