United manager Ole Gunnar Solskjaer opted to make 11 changes to the team that drew 3-3 draw at Sheffield United with seven teenagers in his side.
The Red Devils, having already qualified for the last 32 of the competition, made a strong start against their hosts, who have been Kazakhstan champions for the last six years.
In the fifth minute, Mason Greenwood’s fierce drive forced veteran Astana goalkeeper Nenad Eric to parry the ball and it came as no surprise when United took the lead in the 10th minute.
Luke Shaw created the opening, playing in captain on the night Jesse Lingard, who slammed a low shot from the edge of the box past Eric and into the bottom right-hand corner of the net.
Ethan Laird, who impressed on his United debut, saw his cross-cum-shot saved by the overworked Eric, before Lingard lashed an effort over the bar.
Lingard’s shot landed on the roof of the Astana net as United threatened to double their lead but the home team went close to grabbing an equaliser when their experienced defender Evgeny Postnikov headed a presentable chance over the bar.
Astana sporadically looked dangerous in the first half and Romania international Dorin Rotariu should have done better with a close-range effort that flew wide.
Another United teenager who was making his debut, Di’Shon Bernard, almost sliced a shot into his own net and, after Tahith Chong had missed a golden opportunity, Astana equalised in the 55th minute when Dmitriy Shomko whipped a low shot home.
The match was turned on its head seven minutes later when Astana took the lead – Antonio Rukavina’s cross hitting Bernard and flying into the top corner of the net.
Astana almost added further goals with Runar Mar Sigurjonsson and Roman Murtazayev going close while Eric denied United’s Angel Gomes and Greenwood as Solskjaer’s inexperienced side tried in vain to force a late equaliser.