The KSW lightweight championship will be on the line when Marian Ziolkowski answers the challenge of Sebastian Rajewski in the main event.
Ziolkowski became champion at KSW 57 when he won the vacant title with a sensational TKO victory over Roman Szymanski.
Since that 2020 event, Ziolkowski has successfully defended his belt twice - the first a submission win over Maciej Kazieczko, while the other a decision victory over Borys Mankowski.
This weekend, the defending champion will take on a lifelong martial artist in Rajewski. The 30-year-old is on a three-fight win streak, which includes victories over UFC veteran Niklas Backstrom and former KSW champion Artur Sowinski.
In the co-main event, KSW legend Marcin Rozalski will return to the octagon for the first time in five years.
The former KSW heavyweight champion will square off against kickboxing legend Errol Zimmerman in a special mixed rules fight - a K1 bout contested in MMA gloves and scheduled for three five-minute rounds.
KSW 71 will also mark the MMA debut of former WBC heavyweight title contender Artur Szpilka.
The man who previously shared the squared circle with the likes of Deontay Wilder and Derek Chisora will swap the ring for the octagon as he takes on Ukraine's Sergey Radchenko.
Back in 2020 two men fought in a boxing ring with Szpilka enjoying a controversial decision victory. This weekend, the pair will be looking to settle the score.
Elsewhere, two former champions will go head-to-head as former welterweight title holder, Borys Mankowski, will take on former KSW featherweight champ, Daniel Torres.
Full fight card
KSW Lightweight Title
Champion Marian Ziolkowski (24-8-1) vs. Sebastian Rajewski (12-6)
Heavyweight - Mixed Rules Bout
Marcin Rozalski (7-4 MMA) vs. Errol Zimmerman (103-13 Kickboxing)
K1 in MMA Gloves + 3 x 5 min rounds
Borys Mankowski (22-9-1) vs. Daniel Torres (13-5)
Catchweight 105 kg/231 lb
Artur Szpilka (0-0) vs. Sergey Radchenko (1-1)
Jakub Wiklacz (12-3-1) vs. Bruno Santos (10-3)
Roman Szymanski (15-6) vs. Valeriu Mircea (26-7-1)
Filip Stawowy (9-2) vs. Michal Martinek (9-3)
Donovan Desmae (15-7) vs. Artur Sowinski (22-13)
Marc Doussis (7-1) vs. Przemyslaw Dzwoniarek (3-1)