Adesanya looked confident before the decision was read out and his face showed the disappointment at the decision, although he was not outwardly angry and congratulated Wilnis before leaving the ring without protest.
Many fight fans in attendance booed the outcome.
Television statistics put up after the bout showed Wilnis connected with 134 of 245 strikes, with the most telling numbers being the kicks, as attacking Adesanya's legs saw him land 72 of 81 kicks thrown.
Adesanya's statistics showed he landed 122 of 184 strikes thrown, although when judging kickboxing there are several other factors which come into play - such as accuracy and effectiveness of the strikes, damage done, and control or domination of the bout.
Many Kiwi fight fans took to social media to complain about the decision, among them Kiwi-born UFC fighter Mark Hunt, who fumed on his Facebook page that the television announcers have favoured Wilnis.
"Don't know what fight those commentators was watching, they are total idiots, who hires these bums?
"Good job Izzy, you won, you should of knocked out them stupid commentators."
Adesanya's old sparring partner and former New Zealand champion Kyle Gallacher watched the fight a couple of times, with the sound off, to see if his fellow Whanganui exponent got a bad decision.
"Wilnis had the right strategy - pressed forward and countered with leg kicks," Gallacher said.
"I still thought Izzy won by one round. He would give Wilnis four shots for every one.
"Izzy had the cleaner shots, and the better variety too. I would have liked to have seen a few more knees. Knees score really good [with judges].
"The fight game - you can't leave it to the judges."
Nonetheless, Gallacher said Adesanya had got to showcase himself in front of a massive world wide television audience, showing off his skills, and he would back him to win a rematch.
"He's still on his way to being a superstar."
