The record-breaking champion was joined at the sold-out Arena Ostrow in Poland by UFC heavyweight and fellow Brit Tom Aspinall.
In the post-fight interview, De Fries was interrupted by his countryman who called out five-time world strongest man Mariusz Pudzianowski.
He said: "Let's get that Pudzianowski fight on because these guys are too easy for this guy.
"He's smashing everyone too easy. We need Mariusz Pudzianowski next, come on KSW. Let's make a real fight for this guy, come on."
De Fries, who improved his professional record to 22-6, extended his unbeaten run to 10 straight fights and reinforced his position as the most dominant heavyweight in KSW history.
There was controversy in the co-main event as Tom Breese (15-3) was awarded the submission victory over Damian Janikowski (7-5). The Olympic medallist immediately contested that he did not tap and following the bout both fighters seemingly agreed to a rematch.
Elsewhere, on the card, heavyweight destroyer Darko Stosic (17-5) KO'd veteran Michal Kita (21-15-1) in their rematch, Tomasz Romanowski (17-8) won his KSW middleweight debut with another first round KO, Norway's Emil Meek (10-6) got his first win since 2016, and Georgia's Sofiia Bagishvili (7-1) impressed with a bone-crunching submission win in her KSW debut.
KSW 74 Results
Main Event Heavyweight Title: Champion Phil De Fries (22-6) def. Ricardo Prasel (13-4) via submission (rear-naked choke), round 1, 4:11.
Co-Main Event Middleweight: Tom Breese (15-3) def. Damian Janikowski (7-5) via submission (guillotine choke), round 2, 1:55.
Heavyweight: Darko Stosic (17-5) def. Michal Kita (21-15-1) via KO (punches), round 2, 2:54.
Middleweight: Tomasz Romanowski (17-8) def. Cezary Kesik (13-3) via TKO (punches), round 1, 3:54.
Bantamweight: Werlleson Martins (17-5) def. Pawel Politylo (7-4) via unanimous decision (39-28 x 3).
Welterweight: Emil Meek (10-6) def. Kacper Koziorzebski (8-5) via TKO (elbows), round 2, 2:01.
Strawweight: Sofiia Bagishvili (7-1) def. Anita Bekus (6-3) via submission (straight armlock), round 2, 1:47.
Featherweight: Wojciech Kazieczko (3-0) def. Eduard Demenko (3-3) via unanimous decision (30-27 x 2, 29-28).
Middleweight: Borys Dzikowski (2-0) def. Arkadiusz Mruk (0-1) via TKO (head kick & punches), round 1, 0:40.