Gold Coast may have a case to answer over claims they fielded an extra man during their 24-20 come-from-behind NRL win over Canberra.
The NRL confirmed it would review footage of the match on Saturday at GIO Stadium, where it's believed a 14th player - former Raider David Shillington - went on the field before walking off again in the 48th minute.
He was meant to replace Tyrone Roberts, who went down clutching his knee but continued to play.
Titans coach Neil Henry admitted there was some confusion among officials around the interchange, but said Shillington wouldn't have been on for longer than five seconds.
"The interchange guy is supposed to sight it as far as I know and that didn't happen," he said.
"I wasn't watching that play at the time ... so I wasn't sure what was going on.
"Obviously match officials will have a look at it and we'll see what happens."
It overshadowed what was a remarkable fightback from the Titans, who were down 20-6 with 25 minutes to go.
A converted try to Shillington sparked the turnaround, and Zeb Taia crossed over with five minutes to go before new recruit John Olive was awarded a controversial four-pointer on the siren.
Referee Henry Perenara's on-field call of a try was confirmed by the bunker, although some Raiders players questioned whether Olive planted the ball.
"John Olive is adamant he got it down, but if that's ruled 'no try' (by Perenara) you'd probably go, 'Is there enough evidence to overturn that?'" Henry said.
The victory temporarily sends the once-unfancied Titans into fourth on the NRL ladder, having won three of four matches this season.
It marked their 100th win in club history, and the end of the Raiders' unbeaten start to 2016.
The home side were on track to continue their streak after getting out to 12-0 lead in 13 minutes, then racing out to 20-6 in the second half.
But errors and a costly penalty by Frank-Paul Nu'uausala that led to Olive's try ruined their chances.
"It's been a very similar story the last three weeks ... but obviously this week has gone against us," coach Ricky Stuart said.
"We had the opportunity to win it earlier in the second half and we should've done it. The top teams they do."
To add to their woes, Edrick Lee and Jeff Lima both suffered thumb injuries - a potential break for Lima - that could see them join star halves Aidan Sezer and Blake Austin on the sidelines.
The Titans also will be sweating on scan results, with Roberts suffering possible ligament damage to his knee.
They face Brisbane at home on Friday, while the Raiders play Canterbury at Belmore the following Monday.