But the champion soon discovered that Rashka could be hurt with knees and was coming forward with head low and gloves up.
After both nearly tumbled out of the ring to start the second round, Makatea-Leylander began to search for a place to land the uppercut or to pierce the gloves with the point of his elbow, which opened up a cut on top of Rashka's head.
Having a target as the blood flowed, Makatea-Leylander increased his output in the third round, despite Rashka's best attempts to smoother him into the corners and land a few counter-punches, as the Whanganui fighter unloaded with knee strikes and short elbows in the clinch.
Rashka was swaying and fell face down from exhaustion while throwing a punch on the bell.
The fight had now established its pattern, as Makatea-Leylander was tiring as well but measured some leg kicks, before Rashka again grappled him back into the ropes in survival mode, yet was still unable to keep out every elbow shot.
Makatea-Leylander came out with a flying knee to start the fifth round, but had to settle down to converse his remaining energy as Rashka continued pull him into clinches, while getting off one good leg kick.
Trying to finish with a flourish, Makatea-Leylander went for the rabbit punches to get some room, and then an elbow and spinning back fist on the bell.
It was more than enough to convince all three judges.
"Kyle [Gallacher] did say he was rushing in, so elbows work every time," said the champion after his first title defence.
"Elbows and knees and I'm covered in blood that's not mine.
"No way I'm going to lose in front of my home town."
The fight's gruelling cross-ring wrestling had still taken a toll on Makatea-Leylander.
"I think I broke my toe in the third.
"I was just trying not to dry wrench [in last round] and waited to the last 30 seconds."
He thanked the big sponsor T & L Cars Ltd, as well as the Assassins and Anderson, who had come up from Wellington to stay with him and prepare mentally for their fights.
Wallace could not have been more focused and it showed as he extended his winning streak to eight fights and added the New Zealand Middleweight belt to the mix with the TKO of Mike Kapi (Misfits).
Possessing great timing, Wallace tempted Kapi by approaching with his hands down, but worked hard in close with elbows and punching combinations.
Kapi had a strong overhand right and found the mark with it early, but Wallace re-adjusted and continued his dissection.
In round 2, Kapi tried to switch stances, but Wallace pressed him, taking one good shot in a wild exchange, before going to Kapi's body.
A couple of stinging jabs and then a brutal followup punch dropped Kapi to the canvas, and although he regained his feet, Wallace unloaded and then chased him across the ring, with another brutal punch sending Kapi crashing face down at the bell.
Again, Kapi gamely beat the count and went back to his corner, but it was soon clear he should not continue and the match was waved off.
A precision fighter, for Wallace it had been all about adapting until opportunity opened up.
"I felt pretty slow in the first round. He was holding on to that overhand, that was the one weapon [he had]."
Thanking mum on the house microphone, Wallace said it felt pretty good to call himself New Zealand champion.
After he missed the first Night of Assassins show in March with injury, Anderson gained his redemption with a perfect head kick knockout of Kodie Huffam (Hydras) to win the North Island Welterweight belt.
Back from training in Thailand, Anderson aimed to use his height advantage, but took a while to get going after needing recovery time following two inadvertent low kicks from Huffam, who received a warning from the referee.
Anderson recovered to make a perfect leg sweep on Huffam, who nearly landed on his head at the end of the round.
The second round started with a short exchange, and then Anderson beautifully timed his leg kick and Huffam collapsed flat on his back.
While he beat the count, a glassy-eyed Huffam was staggering and the referee waved it off at the same moment his corner threw in the towel.
Huffam later told Anderson he never saw the kick coming, as the crafty southpaw who fights right-handed had changed stances at the beginning of the round.
"I just switched and waited...then I tried the kick. I knew it was good [shot] because I hurt my foot," Anderson said.
He thanked KPTK in Phuket Thailand, his Wellington gym, family and fiancée for all the support.
"KPTK look after me, Lion Pit look after me, we execute what we train.
"I knew [the belt] was mine, I just had to come in and put the work in."
Results
Undercard
Matt Penny (Pitbull) bt Brent Surge (Fortitude) by unanimous decision; Jordan Griffiths (Jackals) bt Jesse Broughton (TPK) by unanimous decision; Waitohu Ngawera (Pitbull) bt Emily Kara (Assassins) by split decision; MMA fight: Cossack Waaka (Hori MT) bt Aaron Stratford (River City Martial Arts) by split decision; Sam Gourely (Lion Pit) bt Jethro Campbell (TMAA) by TKO; Corey-Lee Robertson (Assassins) bt Stefan Harrison (Freestyle MMA Morrinsville) by unanimous decision; Jade Fleetwood (Fortitude) bt Melissa Dyke (TMAA) by split decision; Che Barlow (River City Martial Arts) vs Colin Rameka (The Pen) was No Contest.
Title Fights
IKBF North Island Welterweight title: Jono Anderson (Lion Pit) bt Kodie Huffam (Hydras) by TKO.
IKBF New Zealand Middleweight title: Brendon Wallace (Assassins) bt Mike Kapi (Misfits) by TKO.
IKBF New Zealand Super Heavyweight title: Moe Hussain (Jackals) bt Lee Kara (Awa Kings) by unanimous decision.
IKBF New Zealand Light Middleweight title: Champion Mike Makatea-Leylander (Assassins) bt Rene Rashka (Hybrid MMA) by unanimous decision.