After 16 months away from the ring and at 40 years old, there were plenty of questions surrounding Gennadiy Golovkin in the lead-up to his middleweight title unification fight with Ryota Murata in Saitama, Japan, on Saturday.

Since suffering a majority-decision loss to Canelo Alvarez in September 2018, Golovkin (42-1-1, 37 KOs) hasn’t resembled the same fighter who rose to the top of the pound-for-pound list and established himself as one of boxing’s most dangerous punchers.

And in the early going, before he scored a ninth-round TKO to pick up a second 160-pound title, Golovkin was lending plenty of credence to those doubters who claim a third fight with Alvarez, planned for Sept. 17, is far past its expiration date.

Murata was landing at will over the first four rounds and was controlling the action as the aggressor. Golovkin’s legs appeared more stiff as he moved around the ring, but he has long been regarded as a slow starter.

Suddenly, in Round 5, Golovkin sent Murata’s mouthpiece flying with his signature right hand, and all those memories of GGG’s greatest hits came to mind. The impressive offensive attack began to flow, the looping right hands mixed in with patient feints and uppercuts.

Clearly, this isn’t the old GGG but an older, more stationary version of the man who became one of boxing’s top stars during his torrid middleweight title run.

After that performance, it’s hard to believe Golovkin has a realistic chance of defeating Alvarez, who’s peaking and currently rated as the No. 1 pound-for-pound fighter by ESPN. But Golovkin ensured the fight had a conclusive ending, and in doing so, showed just enough to maintain a glimmer of hope that he can fight Alvarez on even terms a third time and be competitive with boxing’s top star.

The power is still very real, and as the boxing saying goes, that attribute is the last to erode. Golovkin’s chin, too, is still able to stand up to heavy punches. Murata is a formidable puncher who connected plenty, but GGG never wavered.

There’s another factor, too, that could help even out what Father Time has taken away: competitive vitriol.

Golovkin told ESPN it’s “not personal” between him and Alvarez, but their rivalry and distaste for one another are well-documented. GGG was bitter after his first meeting with Alvarez — a bout Golovkin and the majority of the viewing public seemed to believe he won — was declared a split draw. A very controversial 118-110 scorecard from judge Adalaide Byrd in favor of Alvarez only added fuel to the fire.

When Alvarez tested positive for the performance-enhancing drug clenbuterol ahead of the second fight, which was postponed as a result, the feud reached a new level. Alvarez blamed tainted meat, but Golovkin wasn’t buying it.

Time and again in sports, the cliché is repeated that when there’s a rivalry, you can throw the record books out the window. And that’s certainly true in boxing.

Look no further than Juan Manuel Marquez’s four fights with Manny Pacquiao or Tyson Fury’s trilogy with Deontay Wilder.

Marquez was 38 and had recently been dropped by Michael Katsidis in a win when he met Pacquiao a third time, yet that was his best performance against the legend, a controversial decision loss for Marquez. Of course, Marquez knocked him out in the fourth meeting.

Wilder was counted out heading into his third fight with Fury after he was brutalized in the second meeting. The American was knocked out in the trilogy battle, but not before he floored Fury twice in one of the greatest fights in heavyweight championship history.

Golovkin will now look to add to that long list of aging underdogs looking for one last hurrah, and just maybe, the added 8 pounds for the super middleweight bout will aid him.

After all, Golovkin has fought at 160 pounds most of his career, and it certainly must be more difficult than ever at 40.

Nearing the end of his career, if Golovkin has one great fight left in him, it will need to materialize later this year to stave off Alvarez, who is better — and more active — than ever.