Substitute Colin McMenamin grabbed a late equaliser as Livingston fought back to grab a share of the spoils at Almondvale.
McMenamin and Jason Dair were thrown on in the 70th minute as Lions boss Allan Preston pushed three players up front and the bold move paid off when McMenamin struck with just eight minutes to go.
Dundee United were first to threaten and Mark Kerr volleyed over from just outside the box after just 60 seconds following a Jason Scotland knock down.
Derek Lilley had a low shot for Livingston two minutes later but never seriously troubled Tony Bullock in the United goal.
But United suffered a major blow after just ten minutes when Paul Ritchie - making his debut after signing two weeks ago - dislocated his shoulder after falling awkwardly and had to be replaced by David McCracken.
In the 23rd minute, Manu Dorado connected with a Burton O'Brien corner but Bullock blocked the header and Rubio was wide with the follow-up.
Craig Easton twice came close for Livi as he pushed forward from midfield at every opportunity. First, after 28 minutes he was crowded out as he tried to latch onto an O'Brien pass and then four minutes later he just failed to connect with a Stephen Boyack cross as he slid despairingly in behind the defence.
United's Barry Robson had the best chance of the half, letting fly from 25 yards after a good build-up but his shot cannoned back off the post with McKenzie beaten.
Stuart Lovell then forced Bullock into action seconds later with a dipping shot that the keeper parried.
Mark Wilson opened the second half with a curling shot that was just over McKenzie's crossbar and then after 58 minutes the impressive Scotland Under-21 cap was crowded out as he tried to burst in to the Livi box as United started to press.
The opener finally came in the 61st minute from the penalty spot. Jason Scotland, who had been troubling the Livi defence in the second half, was picked out by Wilson and as he drove in to the Livi area, the Trinidadian was hauled down by Dorado.
Veteran striker and skipper Billy Dodds stepped up to take the spot-kick and although McKenzie went the right way, Dodds' right-foot shot was just beyond his reach.
Derek Lilley had a 62nd minute shot blocked as Livingston pushed for an equaliser and after 73 minutes Lilley again came close when his deflected shot was parried by Bullock with McMenamin inches away from connecting for what would have been a sensational first touch.
The equaliser finally came eight minutes from time and once again it was Lilley who was involved. His angled shot from the left was brilliantly saved by Bullock but the United keeper's parry fell to McMenamin, who stabbed home from close range.
Lilley could have won it in the 86th minute but, unmarked at the back post, headed wide from a Dair cross.
United too had their chances to grab all three points but, deep in injury time, McIntyre's shot on the turn was tipped over by McKenzie.