Injury-hit Leeds looked destined for a first league defeat of the campaign when trailing as they headed into the dying moments of Saturday’s game at The New Den following Jed Wallace’s strike 10 minutes after the interval.
Defeat would have meant a ninth loss from the club’s last 10 visits to Millwall, who also handed Leeds their first league defeat of the season last term under former head coach Thomas Christiansen, also in September.
Leeds also arrived top of the pile in south London 12 months ago but suffered a 1-0 beating en route to a slide down the table to ultimately finish 13th.
One year on, on-loan Manchester City winger Harrison ensured history did not repeat itself at Millwall with the 21-year-old producing a super low finish from the edge of the area in the 89th minute.
Leeds then learned that the division’s only other previously unbeaten side, Middlesbrough, had lost 1-0 at Norwich City.
Harrison said: “It’s important to not get distracted but I think we are definitely a team capable of getting promoted and we just have to keep our heads straight and keep on the same path. This was definitely a big result after realising that Middlesbrough had lost and that Derby had lost as well. It’s a crucial point and we are happy to get one but, in the end, we will be looking to play better and to try and get a win next time.”
Leeds are straight back in action tomorrow evening at home to second-bottom Preston North End, having overcome a spate of injuries to make their point in the capital.
Despite missing strikers Kemar Roofe and Patrick Bamford plus Pablo Hernandez, Gaetano Berardi and Jamie Shackleton, Leeds began positively with 19-year-old Wales international Tyler Roberts handed his first league outing in the lone striker role.
United’s best chances fell to Roberts, who failed to beat goalkeeper Ben Amos after outstripping Wallace to a long ball in first-half stoppage time after Millwall had threatened from set pieces.
Ryan Leonard’s header bounced off Steve Morison into goalkeeper Bailey Peacock-Farrell’s arms at close range from a corner and Morison squandered two good headed chances.
After Roberts had scuffed a good chance across the area early in the second half, a long throw proved United’s undoing in the 55th minute when Leonard’s delivery was flicked on by Jake Cooper for Wallace to fire a low finish in off the post.
Leeds attempted to hit straight back with Luke Ayling denied by a brilliant save from Amos before Roberts saw a weak flicked header saved.
Bielsa then moved Harrison into the lone striker role after Roberts was withdrawn and the move paid dividends following a row between Bielsa and Millwall chief Neil Harris after United’s Gjanni Alisoki attempted to retrieve the ball from the hosts’ technical area.
Moments later, Harrison punished Millwall’s weak efforts to clear a long ball to score his first goal in English football.
Even then the drama was not over with Millwall hitting the post in the second minute of stoppage-time through Tom Elliott’s header before Leeds survived an almighty goalmouth scramble from a corner. Bielsa said: “The main arguments of our opponent are throw-ins, corners, long balls. All of them are legitimate but to impose our style we needed to do more complicated things. We did what we had to do to score.”
Millwall: Amos, McLaughlin, M Wallace, Cooper, Meredith; J Wallace, Williams, Leonard, O’Brien; Morison (Bradshaw 70), Gregory (Elliott 87). Unused substitutes: Martin, Romeo, Webster, Tunnicliffe, Kalak.
Leeds United: Peacock-Farrell, Ayling, Douglas, Cooper, Jansson, Phillips (Forshaw 74), Klich (Baker 61), Alioski, Harrison, Saiz, Roberts (Dallas 68). Unused substitutes: Blackman, Pearce, Edmondson, Clarke.
Referee: C Kavanagh (Lancs).