David Tua comes back from two years of inactivity to meet Shane Cameron in one of those anything-can-happen heavyweight fights in New Zealand on Saturday.

The event is being billed as the Fight of the Century, which maybe it is for New Zealand, a country that has always been a boxing backwater.

Tua looks in good trim at slightly over 237 pounds, but he apparently started training for the fight at almost 300 pounds. The former heavyweight title challenger says he is motivated and has rediscovered his hunger for success, but Tua turns 37 next month and it seems a lifetime ago when he fought that fiercely exciting 12-rounder with Ike Ibeabuchi.

Cameron, 31, is big and strong but limited. He cuts easily and has twice suffered a broken right hand, but his main drawback is that he does not take a punch terribly well. In his only loss he was knocked out in the last round by Friday Ahunanya, who although a capable veteran has never been considered a seriously hard puncher. I understand that Cameron has been wobbled in other fights, and he was stopped in the semifinals of the Commonwealth Games in 2002 although this was on the amateur “outclassed” rule in which a fight is automatically stopped if one boxer has compiled a 15-point advantage over his opponent on the electronic scoring system.

Most people in the game believe that if Tua has anything left at all, he will win this fight, probably inside the distance. Two years is a long time out of boxing, though, for a fighter who tends to pack on weight in between fights — a description that fits Tua.

In his last two bouts before the layoff, Tua looked good, knocking out veteran Saul Montana in the first round and blowing out trial horse Cerrone Fox in the second, but Montana, a former cruiserweight contender, was coming to the end of a long career and had been stopped in three rounds by Tye Fields, while Fox has been stopped in his last five appearances.

Before these fights, there was speculation that Tua might be losing his punching power. It perhaps wasn’t surprising that he was taken the full 10 rounds by Cisse Salif and Robert Hawkins, who are durable survivors, but Tua struggled against Talmadge Griffis before winning in the last round and he was sluggish for six rounds against the southpaw Maurice Wheeler before sinking his opponent with a left hook downstairs in the seventh. However, Tua’s weight was around the 250-pound mark for the Griffis and Wheeler fights, and his weight for the Cameron fight is approximately where it should be. Of course, there is the possibility that shedding weight has drained Tua a little bit, a point that has been raised by the Cameron camp.

Cameron looks in magnificent condition at 227 1/2 pounds and I believe him when he says he has never trained harder or better, but the old saying goes that you can’t put muscles on a chin — we were reminded of that with Bernard Dunne’s defeat in Dublin last weekend.

I have no doubt that Cameron can outwork Tua and build up a lead on points, but can he get through 12 rounds without getting caught by a big punch?

Tua is always dangerous. Fres Oquendo was piling up points for eight rounds, then got caught by a big left hook in the ninth. Talmadge Griffis was doing a good job of blocking Tua’s hook but, with the finishing post in sight, he got clobbered by a huge overhand right. Tua can hurt a man from either side, reminding me of the line from the old song Sixteen Tons: “If the right one don’t get you then the left one will.” Cameron could be doing well, only to get caught and stunned in a momentary lapse of concentration.

Cameron says that if the fight goes to a decision there will be only one winner — him. I think he’s right there, but getting through the 12 rounds will be the challenge.

Tua’s inactivity and weight loss make this a difficult fight to assess because we can’t know how well he will perform until the fight is in progress. I am leaning a bit towards Tua, with his far greater experience, pulling out a KO win when trailing on points, perhaps some time after the seventh round.