Leeds United lead Bristol City 1-0 at half time thanks to a Mirco Antenucci penalty.
Bristol went close to taking the lead in the 13th minute as Callum Robinson's right-footed shot from distance marginally went over the bar.
The hosts had the first shot on target midway through the half, as Jonathan Kodjia forced the keeper into a low save from close range, before Aden Flint's header was cleared off the line from the resulting corner.
Steve Cotterill's men stayed on the front foot as Joe Bryan had an effort saved by Marco Silvestri, before missing the rebound.
Leeds were awarded a penalty towards the end of the half as Antenucci was brought down by Ben Hamer, and the striker stood up and smashed the spot kick down the middle.
Bristol had a chance to draw level before the break but Kodjia's shot from the middle of the box went wide.