Three goals before half-time put Swindon in control at the County Ground, and it was an afternoon to forget for Barnet as Matt Ritchie added another midway through the second half to complete a 4-0 win.
Swindon took an early lead through Raffaele De Vita against the run of play when De Vita took a lay off from Alan Connell to fire low past Dean Brill.
Swindon came into the game encouraged by their goal and doubled their lead on 22 minutes when Ritchie's shot hit the crossbar, rebounded to him, and he fired past Brill.
Mehdi Kerrouche then headed home to make it 3-0 in first-half stoppage time.
Swindon continued to control the game after the break with the visitors' only serious effort a long range dipping shot from Mark Byrne which Phil Smith pushed over.
The home side, with Ritchie having an inspired afternoon, scored the inevitable fourth goal when the Swindon player collected a long ball and went on to beat Brill as the Barnet defence dithered.
Swindon will be happy with the De Vita, Ritchie and Kerrouche goals but Barnet have a good deal of defensive work to do.
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