Ten-man Wrexham ground out a hard-fought win thanks to midfield replacement Kevin Thornton's strike six minutes from the end.
Victory ensured the Dragons remained top of the Blue Square Bet Premier while Barrow remain stuck in a battle against relegation.
Jay Harris was sent off in the 63rd minute for lashing out at Barrow midfielder Alex-Ray Harvey.
But Glen Little combined with Robert Ogleby to give Thornton his chance.
Little and Ogleby also came on as substitutes in the last half-hour as the visitors sought the breakthrough.