The revived Kitwe giants top the table for the first time in over 20 years following their return from oblivion five years ago.
Terry Kayamba and Robert Chilundami crossed the line to place two tries each while Benaya Mukwamba converted both of them.
Mukwamba later added a drop goal and penalty to his tally for the day and Charles Tembo also successfully kicked a spot-kick.
Nkwazi on were on the scorecard through a Wezi Kayamba try and a Laston Mukosa penalty goal.
KPF lead on the table on 18 points from four games played, three points ahead of defending champions Arrows who have played three games.
However, KPF actually sneaked into top spot thanks to fellow unbeaten side Arrows inactivity this weekend.
This is after Arrows opponents Konkola failed to travel to Lusaka from Chililabombwe to fulfil their Week 4 game due to logistical problems.
The match has now been postponed to a later date.
Meanwhile, Eagles are 3rd on 14 points after a resounding 49-0 away win over Chibuluma in Kalulushi.
Mufulira A, Powerhouse Lusaka and Diggers are 4th (11 points), 5th (9 points) and 6th (9 points) respectively and tall hree also won their Week 4 games.
ZRU Week 4 Results
Chibuluma 0 -49 Eagles
Diggers 29-3 Mufulira B
Mufulira A 90-0 Nchanga
Ndola Wanderers 3-5 Powerhouse Lusaka
Nkwazi 8-23 KPF
Roan 11-7 Kansanshi