The Northern Irishman made it 14 goals this season with a second-half hat-trick to help Craig Brown's side stay within touching distance of the top four with a 3-1 win.
Hibernian stole the headlines with a memorable win against Celtic, courtesy of an early finish from young striker Leigh Griffiths. A long ball forward caused chaos in the Celtic defence, with Griffiths taking full advantage to slot home the winner from close range.
Motherwell battled back from two goals down to claim a point against Kilmarnock and stay third in the table. The visitors were ahead thanks to goals either side of the interval from Borja Perez and Paul Heffernan. Jamie Murphy kick-started the comeback with his 50th goal for the club before Henrik Ojamaa struck for the second time this season to level the match.
SPL results in full: Dundee 1-3 Aberdeen, Hibernian 1-0 Celtic, Motherwell 2-2 Kilmarnock, St Johnstone 0-0 Inverness