Tackle-busting second-rower Liam Wiscombe produced a 25m run through the Tigers' defence to reduce the margin to two points before Jenkinson showed tremendous composure to slot the goal from 10m to the left of the posts for a 28-all result.

"It was a really good effort and there's plenty of promising signs," delighted coach Adrian Purtell said.

"The effort that everyone was willing to put in for each other was something that you can really build on.

"Hopefully it stands us in good stead for a successful season."

The Thunder had a heartbreaking run of close losses last season, falling by 10 points or less in eight games.

Former NRL player Purtell will be hoping the gritty comeback is a positive sign and last year was just bad luck.

The Tigers stunned the visitors, racing to a 12-nil lead after only nine minutes.

The Thunder steadied through winger Ty Tindalevale and when former Bombala forward Luke Ingram scored two tries in five minutes, the visitors had a shock four-point lead at half-time.

And the underdogs extended the margin when Kiwi Sabastian Rapana crossed at the 17-minute mark of the second half, Jenkinson's conversion pushing the lead to 10 points.

But Gundagai launched a 14-minute blitz, scoring three tries to grab a 28-22 lead with seven minutes left.

Tigers' recruit Mathew Lyons scored one of those and he looks like being a quality newcomer after spending time in Canberra.

It looked like deja vu for the Thunder from last year until Wiscombe's barnstorming effort and Jenkinson's coolness.

"In the past when we got behind we might have been kicking the dirt, but to fight back was enormous," president Rick O'Connell said.

"Luke Ingram was huge, he was everywhere, (halfback) Robbie Byatt was good, both our front-rowers Brad Hill and Brad Nicholson were great, Joe Lumb played the full 80 minutes, Adrian was strong, we didn't have a bad player."

The only negative was a potential broken jaw to centre Damian Scott, with officials hoping for some good news on that injury front.

The Thunder will now host Wagga Brothers.

They had a two-point loss to Tumut in the season opener, while Temora stunned grand finalists Southcity.