Some of them are shadier than others. Put this one down as more surprising than dubious. Tillman isn't exactly Wladimir Klitchko, and Williams might just be a bit better than he has been given credit for. Williams is a remarkable athlete who dedicated himself to improving at the sport for a solid two months. He received expert tutelage. Clearly that paid off.
Still, there will be doubters. They will remain until Williams proves himself consistently in the ring. For now, though, the SBW legend has just grown another set of legs. And fists. New Zealand has a new heavyweight champion.
Boxing promoters will already be salivating at the thought of what might be. SBW v Shane Cameron? SBW v David Tua?
You could pave a few streets with shiny stuff if those contests ever came off.
Early demolition jobs were the theme of the night in Hamilton, with ringside interviews lasting longer than the fights.
Fans hoping for a meaningful contest the early portents were far from positive. The evening's opening bout saw Papatoetoe computer programmer Dickey Peirera enter the ring in bare feet and exit after being KO'd by Rocky Jerkic in less time than it takes to lace a pair of boots.
Remarkably, an even greater mismatch was yet to come, with some-time corporate charity fighter Todd Crawford lucky to escape serious injury after being pitched in with promising Australian middleweight Bilal Akkawy. Thanks to some prudent refereeing those fights were mercifully allowed to continue only for a combined 108 seconds.
With former NRL player Jason Williams knocking over Porirua security guard Clint Fotai in two rounds, the early fare was painfully brief.
Undefeated Kiwi cruiserweight Robert Berridge finally provided a watchable contest, dismantling rugged
Samoan Faimasasa Tavui in a clinical four round display to improve to 13-0-1.
Former Commonwealth games representative David Aloua also impressed, knocking out Monty Filimaea with a crashing right hand with two seconds remaining in the second round.
Both Aloua, who improved to 6-0 with a 100 per cent knock out ratio, and Berrdige are fashioning tidy careers and are fighters worth keeping an eye on. So too, it must now be said, is the name Sonny Bill Williams.