The first two goals, 1–0 and 2–0, mean that Haaland has scored 30 goals in 25 games in the Champions League.
No one else has managed to reach 30 hits so quickly.
1-0 came on a penalty and the second on a header after Kevin de Bruyne hit the crossbar.
In the final minute of the first half, Haaland then stayed in front again, after the ball danced on the goal line after a corner.
The 22-year-old luckily got the ball on him after a defender failed to clear.
Emil Forsberg plays from the start in Leipzig.
The match is in progress.