Needing just two overs to claim his five wickets, Williams' haul required the fewest balls in worldwide Twenty20 history, while no bowler had ever been introduced as late as the 18th over and ended with a five-for.
Williams was ecstatic with his performance, and how it contributed to the team's victory.
"There were certainly a few nerves flying around at the end there but to get over the line — especially as it keeps our campaign alive — it's an unreal feeling," he told Radio Sport.
Williams' spell actually started sedately, going for four runs from his first three balls, as Wellington's equation was reduced to 19 runs required from 15 balls. Then, he struck, bowling Fraser Colson, having Lauchie Johns caught in the deep, and completing his hat-trick – his first since school cricket –with a superb one-handed catch to remove Jamie Gibson.
Despite his heroics, the game wasn't sealed yet, as Wellington took seven runs from Ed Nuttall's 19th over to leave them needing 12 from the final over.
It was no surprise when Williams was handed the ball, and while admitting to some serious nerves, he was ready.
"I've been practising for those sorts of situations, it's all about execution. Restriction is key, and wickets are the easiest way to restrict them."
Those nerves increased when Logan van Beek and Peter Younghusband took eight from his first four balls, leaving four needed from the final two deliveries of the match, but Williams drew Younghusband into an attempted match-winning shot, with Chad Bowes pocketing a catch at long-off.
Van Beek's attempted heroics off the final ball ended in the same result — Bowes taking the catch, and Williams ending with 5-12, as well as memories for a lifetime after a career-best display.
"I think my best before this was about 2-10," Williams said with a laugh.
"A marked improvement."
