For the third time in pre-season, United's Reserves fought back from a two-goal deficit to avoid defeat - this time against Chelsea.
Late strikes from Fabio da Silva and Darron Gibson - the latter from the penalty spot - preserved Ole Gunnar Solskjaer's unbeaten record since taking the second string's helm.
United looked decidedly off-colour in the opening exchanges, and Jacob Mellis beat the Reds' offside trap to slot the hosts ahead just after the half-hour.
Ben Amos was again beaten in first half injury time, and again he had no chance as Scott Sinclair powered home a fine header from Carl Magnay's cross.
The Reds' occasional menace became a constant threat after the interval, however, and Blues goalkeeper Rhys Taylor had to be alert to save fine efforts from Danny Drinkwater and Kiko Macheda.
Drinkwater also struck the upright as he came desperately close to a fifth pre-season goal in as many games, but it was Fabio who reduced the arrears, thumping a 25-yard effort into Taylor's top corner.
United were in the ascendancy and kept pushing for a route back into the game. It came three minutes into stoppage time, when a foul by Liam Bridcutt on Drinkwater gave Gibson the chance to level from the spot.
The midfielder stepped up and converted comfortably, snatching a draw in a pulsating encounter and continuing the list of promising performances from Solskjaer's side.