Emerging allrounder Hayden Kerr hit a last-ball four to cap a remarkable innings as shorthanded Sydney Sixers kept their dreams of a historic hat-trick of titles alive with a dramatic victory over Adelaide Strikers to reach the BBL 2021-22 final.

Needing two runs off the final delivery, promoted opener Kerr - who had mostly batted at No. 8 this season - sealed a triumph for the ages and signalled his allround talent with 98 not out off 58 balls. His winning runs were punctuated by a roar from the SCG faithful while Strikers were crestfallen as their six-match winning streak, and season, ended in heartbreak.

Sixers meet Perth Scorchers in Friday's final at Marvel Stadium but have just 12 healthy players on their list. They endured late upheaval with star opener Josh Philippe ruled out after testing positive to Covid-19, while batter Daniel Hughes failed to recover from an ankle injury sustained in the warm-up of the qualifying final against Scorchers. Jay Lenton, an assistant coach for Sixers, only found out six hours before the game that he would be taking the gloves. The former Sydney Thunder player last played competitive cricket for Manly in Sydney grade cricket just before Christmas. But was there at the end watching Kerr hit the winning runs.

They were further handicapped by injuries to batter Jordan Silk and veteran spinner Steve O'Keefe while in the field. With Philippe sidelined, Sixers launched a second bid for superstar Steve Smith to play but it was again blocked by the BBL which stuck with a decision that has been widely ridiculed.

But it didn't matter as Sixers found a way and a new hero emerged.

Sixers' apparent jinx meant they needed to experiment and they punted with Kerr as an opener with the 25-year-old having briefly filled the role two seasons ago. Despite Kerr's innate self-belief in his batting, his BBL career high score of 22 didn't exactly inspire confidence.

But the BBL's second highest wicket-taker this season showcased his prowess with the bat as Kerr - who bats right-handed and bowls with the left - produced an all-time great innings to unexpectedly get the depleted Sixers over the line.

He was lucky early and appeared rusty, having been generally used at the death as the finisher. Kerr, who was named in ESPNcricinfo's Team of the Tournament on Monday, should have been dismissed on the first ball of the innings and on 16 but rode his luck to play a blinder. He found invaluable support from Sean Abbott, who smashed 41 from 20 balls before falling off the first ball of the final over.

But Kerr hit Harry Conway for a six off the fourth ball and then finished the job but not before some controversy. With Silk ailed due to a hamstring injury, he was retired hurt before the last ball but it didn't matter as Kerr soon had spectators jumping with joy.

Strikers' strong attack would have fancied their chances against an unusual Sixers batting order but they struggled against an unexpected onslaught from Kerr. They were under pressure with Sixers rolling at 2 for 96 in the 14th before Peter Siddle seemingly turned the match with a brilliant yorker - not for the first time this season - to dismiss his opposite number Moises Henriques.

But Kerr couldn't be stopped and it came down to the final over. Conway, who was the last-over hero against Sydney Thunder in the Knockout, appeared to be again holding his nerve but couldn't repeat his heroics this time around.

Strikers will rue their chances against Kerr with wicketkeeper Alex Carey missing a stumping on the first ball of the innings and then Matt Renshaw dropped a sitter on the boundary when he was on 16.

Their remarkable late-season revival ended in tears.

Abbott stood up when his team desperately needed him to. The 29-year old has been uncharacteristically out of form with just one wicket in his last four games and he's also been expensive.

But a pumped-up Abbott enjoyed the extra bounce on the SCG deck, which accounted for dangerous Matt Short who edged to slip. He then bowled a gem around the wicket to take out Travis Head's middle stump and later claimed Ian Cockbain.

He will need to fire again in the final with O'Keefe injuring a right calf after his bowling stint meaning his superb BBL career might be over.

Strikers' top-order batting was blown away inside the four-over powerplay with Head enduring his third straight single-digit failure since his Ashes heroics.

Cockbain and the ever-reliable Jonathan Wells launched a comeback as Strikers built a respectable total. Wells again delivered to reach his fourth half-century of the season.

But Strikers rued the top-order failures of Head, Carey and Short as their total proved just not quite enough.