The Under 20s defeated their Motherwell counterparts 3 - 0 at Tannadice tonight with goals from Thomson, Gauld and Gilmour and move back up to second place in the Under-20 Youth League.
If Ryan Gauld was the star of proceedings, scoring once and instrumental in the other two goals, this was a Tangerine side without a failure.
Making a belligerent start, it took United just seven minutes to take the lead.
Visiting keeper Ross Stewart couldn't hold a Scott Fraser drive from the edge of the box and Ryan Gauld collected it before unselfishly squaring the ball for Robert Thomson to tap into the empty net.
Thomson went close after 16 minutes, Stewart doing well to palm his low drive past the post.
But three minutes later, Gauld doubled the hosts' lead when he slotted home a spot-kick after he had been brought down by Steve Saunders.
Motherwell's best effort of the night was a shot from the edge of the box which Philip Anderson did well to turn round the post.
United continued to dominate in the second half and Stewart only held a Ryan Ferguson effort at the second attempt after 57 minutes.
But five minutes later, Gauld's inspired back-heeler found Ross Gilmour inside the box, but he was clumsily brought down by Chris Humphries for the second penalty of the night which Gilmour duly converted.
Dundee United: Anderson, Gilmour, Tornstrand, Johnston, Spark, Dow, Smith, Fraser, Ferguson (M Russell 73), Gauld, Thomson (Allan 73).
Substitutes not used: McGovern, Lundie, Bell.