Borussia Dortmund fought back from conceding an early goal to beat Wolfsburg 3-1 on Sunday (AEDT), with star striker Haaland netting its third shortly after coming on from the bench.
Wout Weghorst had put the hosts ahead before Emre Can equalised from the spot before the break. Donyell Malen put Dortmund ahead 10 minutes into the second half, and Haaland's goal came in the 80th minute.
The win took Marco Rose's team ahead of Bayern Munich and into top spot before the champion's meeting with Arminia Bielefeld later in the day.
Haaland had been out of action since playing in Dortmund's 4-0 defeat to Ajax in the UEFA Champions League on 20 October (AEDT).
He was only passed fit for the bench, but wasted no time in netting his 13th goal of the season in just his 11th appearance, the Norway forward stretching to cushion in Julian Brandt's cross on the volley.
Haaland's half-century of Bundesliga goals have come from just 50 appearances in the competition.
No other player has reached the milestone in as few appearances or at such a young age – 21 years, four months and six days.
Haaland has averaged 1.12 goals per 90 minutes played in Germany's top flight, scoring 40 with his left foot, six with his right and four headers.
Since Haaland made his Dortmund debut on 19 January, 2020 (AEDT), only Robert Lewandowski (98) has scored more goals than Haaland (71) among players from Europe's big five leagues across all competitions.