The hosts, who secured an impressive 1-1 draw with Paris St-Germain on their Champions League debut on Tuesday, suffered an early setback when they lost defender Gabby George to injury in the ninth minute.
But they recovered to carve out the better opportunities, coming closest to opening the scoring in first-half stoppage time when Hinata Miyazawa struck the underside of the bar.
Lucia Garcia also forced a good save from Leicester keeper Janina Leitzig before the break.
Leicester, who had won all three of their games prior to this fixture, were second best for large periods but snatched the lead early in the second half when Aileen Whelan turned in at the back post following a free-kick.
Manchester United responded well to that blow and deservedly equalised through Maya Le Tissier’s header.
United goalkeeper Mary Earps tipped over a strong Lena Petermann effort, while Nikita Parris put a header straight at Leitzig in the final seconds as both sides pushed for the winner.
The result means Leicester are second in the Women’s Super League, with Manchester United fifth.
The hosts will be disappointed not to take the victory given the many chances they had, but this was another battling display by the Red Devils.
They have conceded the first goal in every game they have played so far this season but have recovered each time to remain unbeaten in all competitions.
Manchester United went into this game looking to build on their impressive second-half display against PSG in midweek, and they certainly had the opportunities to win this game quite comfortably.
As well as Parris’ late chance, Rachel Williams headed over moments before the final whistle.
They missed the creativity of Geyse, who changed the game against PSG when she came on, as she was rested.
But a draw against a side who had won every game they had played so far this season is a decent result and once again highlights the fighting spirit of Marc Skinner’s side.