Wellington's first win over Tasman in 12 years on Wednesday night was overshadowed by a shocking TMO howler.

The Lions got their semifinals hopes back on track with a 25-19 victory in Nelson thanks to tries from Connor Garden-Bachop, Sione Halalilo and Xavier Numia.

But it was TMO Cory Eggers who made perhaps the most notable act of the night, leading fans to label the officiating "completely amateur".

After a fairly uneventful first quarter of the game, Wellington appeared to score a try in the 28th minute with winger Garden-Bachop showing good athleticism to touch the ball down in the corner despite desperate defence from All Black Sevu Reece.

After referee Brendon Pickerill first awarded an on-field try, the decision was sent up to the TMO to check if Garden-Bachop was in touch – with replays showing the Wellington No 11 clearly had his hand in touch before grounding the ball.

Replays showed Connor Garden-Bachop was clearly in touch before grounding the ball. Photo / Sky

But after three looks at the replays, the try was inexplicably awarded by the TMO to the surprise of television commentators and possibly even Garden-Bachop himself.

Former All Black Kane Hames, who was part of the Sky Sport commentary team, later cleared up the incident after speaking to Eggers, who admitted his mistake.

"The TMO is sitting right next to me and I did have a chat to him," Hames said. "He didn't actually look at the left hand, he missed it. He's just seen the replay again and he's gutted. So there's the explanation."

Fans and pundits took to social media to express their shock at the try being awarded.

The try summed up Tasman's night – and season so far which has been plagued by injuries and players lost to the All Blacks – as they couldn't quite match Wellington in a close back-and-forth affair, with the visitors ultimately securing the six-point victory with the help of the controversial try.

The win takes Wellington to third place in the Odds conference with four wins out of six, while Tasman sit in fifth in the Evens conference.

Both teams are back in action on Sunday, with Tasman taking on fellow strugglers Taranaki. Wellington will host Otago at the capital.