Ponga has been named on New Zealand's extended bench for Saturday night's do-or-die showdown with Tonga in Newcastle, just 22 days after breaking his forearm in a dazzling fullback duel with Walsh in the tournament opener.
And Walsh on Tuesday retained the Australian No.1 jumper ahead of James Tedesco for the Kangaroos' semi-final against Samoa in Sydney on Sunday.
While young gun Keono Kini will again start as custodian at McDonald Jones Stadium, Ponga's inclusion is a firm indication the Newcastle Knights superstar will return for the final should the Kiwis make it.
Coach Stacey Jones also selected hooker Phoenix Crossland among the Kiwis' extended reserves as Australian Test coach Kevin Walters made the most significant move of his tenure by picking Walsh over Tedesco.
The selection dilemma has bubbled along through Australia's three group-stage wins.
Tedesco entered the World Cup in exceptional form after helping the Sydney Roosters to the NRL premiership, while Walsh had spent the last two months on the sidelines with an ankle injury.
But Walsh - the star of last year's Ashes series - has done enough to win the backing of former Broncos coach Walters for the business end of the tournament.
Walsh and Ponga were both electrifying in Australia's 24-22 win over New Zealand last month, before Walsh was man of the match with a hand in five tries in last Saturday's 66-6 rout of the Cook Islands.
In other key Australian selections, Bradman Best has made the left centre spot his own by seeing off the challenge of South Sydney talisman Latrell Mitchell.
Tedesco and Mitchell are both part of a six-man bench that includes Canberra's Ethan Strange and Cameron Murray for the likely Allianz Stadium sell-out.
Tom Dearden and Cameron Munster will line up together in the halves.
"Samoa were very impressive in a physical battle which had a lot of emotion last weekend against Tonga and we know we are in for a tough contest on Sunday night," Walters said.
"It's going to be a great occasion in front of a full house at Allianz Stadium, and we've got to meet the occasion with our best performance of the tournament."
Samoa have made just one enforced change with Ronald Volkman replacing Chanel Harris-Tavita (hamstring) at five-eighth.
In the other semi-final, Tonga are unchanged while Crossland remains an option to feature for the first time since his four-match suspension for his leg-breaking tackle on Nathan Cleary in the NRL preliminary final.
The Newcastle hooker was officially elevated to New Zealand's squad on Monday night after forward Jacob Laban was ruled out with injury.
Jones has named Charnze Nicoll-Klokstad on the wing as a result of Ronaldo Mulitalo's one-game ban for a shoulder charge against Fiji.
11°C