Aberdeen moved into sixth place in the Bank of Scotland Premier League as they left Livingston clinging to their top-flight status.
Dons captain Russell Anderson headed home a Jamie Smith cross in the 17th minute to break the deadlock.
Steve Lovell then turned in a 63rd-minute Ferne Snoyl corner and the Dutchman rounded off the scoring with nine minutes remaining.
But Livi were unfortunate not to have scored though after hitting the frame of the goal twice in the first half through Sam Morrow and Dave Mackay.
However, with eight games remaining, the West Lothian club are still nine points from safety.
The first scare for Aberdeen arrived in the 10th minute when slack marking allowed Morrow to flick a Richard Brittain free-kick against the base of the post, before Mackay hooked the rebound wide.
However, Aberdeen composed themselves and, within six minutes, had powered into the lead.
After Snoyl's corner was only cleared back to the on-loan Feyenoord midfielder, he worked a neat passing exchange with Smith.
And, from the former Celtic winger's cross, Anderson met the ball with a header to score his sixth goal of the season.
Livi keeper Roddy McKenzie saved well in the 24th minute when he blocked a Chris Clark drive with his legs.
Smith then tried his luck from 30 yards with a drive which flew harmlessly over the crossbar, but Aberdeen were having trouble breaking down their opponents.
The Almondvale side coped with all the Dons could create during a tight opening 45 minutes and were unfortunate not to draw level in first-half injury time when Mackay saw an opportunistic effort from 20 yards strike the face of Jamie Langfield's crossbar.
Livingston started the second half well and were unfortunate not to draw level in the 50th minute when Wes Hoolahan's weighted through ball sent Mackay scampering down the right.
The former Oxford defender produced a fine low cross into the area which flashed along the goalline, but Allan Walker was just a yard off the pace to meet the ball.
The Almondvale outfit continued to look threatening in attack and Morrow was unlucky to see a 20-yard shot in the 61st minute curl just wide of Langfield's far post.
And, two minutes later, Aberdeen doubled their advantage through Lovell.
McKenzie had produced an excellent save to tip a Scott Severin header from Smith's corner over the crossbar.
However, from the set-piece, Anderson flicked on Snoyl's inswinging delivery and the alert Lovell was on hand to turn the ball into the net from six yards.
With nine minutes remaining Aberdeen put the result beyond doubt as Snoyl opened his account for the Dons with an easy finish.
The midfielder provided a cross which Stevie Crawford turned on to the post, before Severin drew a fine save from McKenzie with a low drive which the former Hearts goalkeeper dropped to parry.
However, the ball only carried as far as Snoyl and he calmly tuned the ball into the empty net to ensure the Pittodrie side leapfrogged Motherwell and Inverness in the SPL table.
Teams
Aberdeen Langfield, McNaughton, Anderson, Diamond,Smith (Foster 87), Dempsey, Severin, Clark, Snoyl,Crawford (Mackie 82), Lovell (Stewart 86).
Subs Not Used: Kelly, Macauley, MacFarlane, Griffin.
Booked: Dempsey.
Goals: Anderson 17, Lovell 63, Snoyl 81.
Livingston McKenzie, McNamee, Dorado, Strong, Mackay,Brittain (Hislop 70), Hoolahan, Walker, Dorrans (Whelan 53),Adams (Healy 81), Morrow.
Subs Not Used: Roy, Miller, Tierney, Vincze.
Booked: Dorado.
Att: 9,229
Ref: S Conroy (Scotland).