New Manchester United coach Erik ten Hag demanded his team take heed of their "unacceptable" second-half lapse after a 2-2 friendly draw against Aston Villa on Saturday. United let slip a two-goal advantage to end Ten Hag's winning run in the final game of their pre-season tour of Asia and Australia. United, wearing their white away shirts, exhibited their newfound attacking flair in a dominant first half, but conceded a header to Villa's Calum Chambers in the dying seconds amid inclement conditions at Perth's Optus Stadium marked by a soggy pitch.