Leeds were wobbling, but a half-time team talk and some vocal backing from their supporters steadied them. Sheffield United were under the cosh again and Roberts was desperately unlucky not to score when his side-footed shot came back off the post with goalkeeper Dean Henderson beaten.
Klich, again, deserved credit for having the vision to pick him out from the byline, although worryingly that made it nine attempts on goal and none on target.
Statistics like that tend to be damaging and so it proved as Leeds captain Liam Cooper lost the ball to Sharp, who squared for Basham and he carefully guided a low shot into the bottom corner.
Celebrating in front of the delirious travelling supporters, Sheffield United knew the damage they had done. There was a roar of defiance from the home fans, but there was also fear and exasperated looks.
Bielsa sent on Barry Douglas and Jack Clarke to try and rescue the situation, but Leeds still could not take their chances, Jansson somehow putting the ball wide from inside the six-yard box, Roberts unable to control the ball when in on goal.
Moments later and after another mistake by Cooper, aided by the otherwise impressive Kalvin Philips, Leeds were down to ten men when Casilla brought down Sharp outside of his area, forcing Jansson to go in goal in injury time.