Rockets were left needing 14 from the final set, but Root, entirely unruffled, belted the spinner's first delivery for six and then found a boundary through midwicket
Cardiff: Welsh Fire 150-6, Trent Rockets Welsh Fire 152-7 - Trent Rockets won by three wickets
Joe Root delivered a batting masterclass at Sophia Gardens, hitting his second successive half century as Trent Rockets snuck past Welsh Fire with a ball to spare to confirm their qualification for the knockout phase.
In a frenetic match, David Payne thought he had dismissed Root for a duck, only for the umpire to signal a no-ball after replays showed the bowler had over-stepped. The England run-machine promptly hit the subsequent free-hit for six over long-on and eventually finished unbeaten on 64 from 41 to secure a three-wicket win, keeping his composure in a chaotic finale.
Set 151 for victory, the Rockets appeared to be cruising after a 66-run opening stand between Root and Tom Banton (32 from 20) but when Rehan Ahmed fell to Saif Zaib and Max Holden holed out to deep cover off Chris Green, the nerves began to show.
Tom Moores went for a big shot and was caught at mid-on to give Green his second and then three wickets fell in the space of seven deliveries as Fire set alarm bells ringing.
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Joe Root played a key hand for Trent Rockets (Clive Mason/Getty Images)
Rockets were left needing 14 from the final set, bowled by Green, but Root, entirely unruffled, belted the spinner's first delivery for six and then found a boundary through midwicket from the second. A single brought Sam Hain on strike, and he crunched the ball through the covers to seize a thrilling victory.
Fire have had a tough season, winning just two of their seven matches, but they had given themselves a fighting chance after Steve Eskinazi's first half century of the campaign headlined a competitive total of 150 for 6.
Runs were hard to come by early on as the Rockets seamers bowled tightly, conceding just 47 from the first 45 deliveries. Steve Smith gloved behind for eight off Sam Cook (2 for 17), who then dismissed Jonny Bairstow, caught at backward-square by Lockie Ferguson for an uncharacteristically scratchy 13-ball eight.
Eskinazi (53 from 42) and skipper Tom Abell (48 from 29) picked up the pace in the second half of the innings before falling to consecutive deliveries in the penultimate set – the former run out after a mix up and the latter caught behind off David Willey – and a breezy four-ball 11 from Green took the hosts to 150, but it wasn't enough to lift them from the bottom of the table.
Rockets, meanwhile, have secured a top-three finish with a game to spare as they aim to repeat their title triumph of 2022. Victory in their home fixture against Birmingham Phoenix on Wednesday could yet see them top the table and progress straight to the Lord's final if other results go their way.