Albury handed Junee's finals hopes an almost fatal blow after scoring 18 unanswered points in the second half at Laurie Daley Oval on Sunday.
It was a typical barnstorming performance from the teenager.
The visitors led 12-0 at half-time after tries to Jon Huggett and Keanau Wighton crossed for tries.
"We were going into a strong wind in the first half and the boys altered their kicking game a little bit," sidelined coach Adrian Purtell said of the conditions.
"It was hanging up there in the wind, so we went along the ground a bit more and it allowed us to get a bit better field position than we were in the first few sets.
"I thought we got in the arm wrestle really well and in the second half our kick chase, the first couple of plays defensively were really good."
But just as the visitors scored two tries against the breeze, the Diesels did likewise for a 12-8 scoreline.
However, Junee had no answer to Wiscombe's power and timing out wide as he raced in the three tries.
"I think we can take a lot of confidence out of the game, it was always going to be a tough place to go Junee and in the conditions we just had to go up and get a result and I'm really proud of the boys' performance," Purtell said.
Apart from Wiscombe the English front row of Brad Nicholson, Joe Lumb and Brad Hill was terrific in the heavy conditions, which was more like home for the trio.
Huggett and five-eighth Robbie Byatt also played well.
Thunder now faces a monster home clash against grand finalists Southcity on Saturday.
The Bulls went into round 13 with the competition lead, but slipped to second after a to a 16-10 loss to Tumut.
The result didn't help the border club's hopes of jumping above Tumut into the top three and double chance.
Thunder's clash against the Bulls, followed by an away game against Tumut, could well decide the top three.
The team will need to realistically win at least one of the games to have any hope of finishing with the double chance.
The loss leaves Junee three wins, and percentage, behind fifth-placed Brothers.