The 20-year-old made German league history in Bavaria last January by becoming the first player to score a hat-trick off the bench on his debut at Augsburg.
Having come on with Dortmund 3-1 down, Haaland needed just 20 minutes to complete his hat-trick and seal a 5-3 win which underlined the Norwegian's status as one of Europe's most electric finishers.
He netted twice last Saturday in a 3-0 home win over Borussia Moenchengladbach on the opening weekend of 2020/21 as holders Bayern Munich - who are away to Hoffenheim on Sunday - posted an 8-0 demolition of Schalke.
Haaland's double left him on 18 goals in 20 games for Dortmund since his January transfer from Red Bull Salzburg.
After netting a penalty against Gladbach, Haaland showed blistering pace to finish a counter-attack sparked by Jadon Sancho.
Haaland puts his form down to frequent ice baths and special light-filtering glasses.
"I see this as a key to squeezing out a few percent more power," he told Dortmund newspaper Ruhr Nachrichten.
Blue-light filtering glasses in the evening "help me get a deeper and better sleep.
"It's all about small details and percentage points to get better every day" in Haaland's quest to be "even better, more clinical, more uncompromising".
Dortmund head coach Lucien Favre is expected to again start 17-year-olds Jude Bellingham and Giovanni Reyna who impressed against Gladbach.
Bayern have won all 14 league games dating back to February and Favre refuses to hear any talk of Dortmund stopping them win a ninth-straight league title.
The two clubs square off for the German Super Cup on Wednesday in Munich.
"Bayern are the best team in the world, they have so much quality and anyone who can't see that is the wrong job," an irritated Favre told reporters.
Also Saturday, Bayer Leverkusen's Czech striker Patrik Schick faces former club RB Leipzig, where the 24-year-old spent last season on loan before being sold by AS Roma.
Leipzig showed they can live without goal-scorer Timo Werner - who joined Chelsea on the back of a 28-goal spree in the Bundesliga - in Sunday's 3-1 win over Mainz.
Yussuf Poulsen and Mali midfielder Amadou Haidara provided the goals after playmaker Emil Forsberg converted an early penalty.
It will be interesting to see how Mainz 05 cope at home to VfB Stuttgart after their squad went on strike at the start of the week in solidarity with Hungary striker Adam Szalai, who was told he has no future at the club.
Stuttgart will hope captain Gonzalo Castro can inspire a first league win at Mainz since September 2005.
Schalke and visitors Werder Bremen both urgently need three points on Saturday night after heavy defeats on the opening weekend.
Head coach David Wagner is under huge pressure after the drubbing at Bayern left Schalke winless in their last 17 matches.
Likewise, having only just avoided relegation last season, Bremen boss Florian Kohfeldt is feeling the heat after losing 4-1 at home last weekend to Hertha Berlin.
One to watch: Alexander Sorloth
RB Leipzig acquired a Norwegian striker of their own in mid-week when Alexander Sorloth signed from Crystal Palace.
After struggling in a Palace team fighting relegation, the 24-year-old spent last season on loan at Turkey's Trabzonspor where he netted 33 goals in 49 games.
He is set to make his Bundesliga debut at Leverkusen.
77 - the average minutes it takes Haaland to score a Bundesliga goal.
48 - the goals Augsburg have conceded against Dortmund, more than any other Bundesliga club.
4 - Bremen have won their last four away games at Schalke.
Fixtures (all times 1330 GMT unless stated)
Hertha Berlin v Eintracht Frankfurt (1830)
Borussia Moenchengladbach v Union Berlin, Bayer Leverkusen v RB Leipzig, Mainz 05 v VfB Stuttgart, Augsburg v Borussia Dortmund, Arminia Bielefeld v Cologne, Schalke 04 v Werder Bremen (1630).
Hoffenheim v Bayern Munich, Freiburg v Wolfsburg (1600)