Sydney Roosters have jumped to the top of the NRL ladder with a gutsy 18-14 win over arch-rivals South Sydney.
The Roosters proved their premiership credentials on Friday night with a win built on staunch defence as Souths dominated field position but couldn't deliver the killer blow.
Both sides suffered casualties, with Souths fullback Alex Johnson leaving the field after two-and-a-half minutes with a hamstring injury in front of 26,331 fans at ANZ Stadium.
While his Roosters opposite James Tedesco missed the last 12 minutes due to a head knock after copping friendly fire from Latrell Mitchell.
Sam Burgess had a shocker, making five errors from 20 carries, including dropping it with his side on the attack with less than three minutes to go.
The result sees Trent Robinson's side jump ahead of Souths but Melbourne have a chance to regain the competition lead when they take on Cronulla on Sunday.
When the Roosters went the length of the field in three plays for Joseph Manu to touch down in the right-hand corner, they had a six-point advantage 13 minutes after halftime.
A Mitchell penalty put Roosters in front by eight and ultimately Souths couldn't run them down.
The hosts set up a grandstand finish when Braidon Burns flicked a pass behind his back for Hymel Hunt to cross and peel their deficit back to four with 15 on the clock.
However, the Roosters held firm to prove they're the real deal.
Souths halfback Adam Reynolds appeared to carry a leg injury and made five errors in what was a forgettable performance.
When asked if his side were now premiership favourites, Robinson said: "No.
"It can't change within a night. We haven't been there all year.
"And it's insignificant as well. It's changed three weeks in a row. Within eight days we've had three (competition favourites)."
Seibold said it was unclear how long Johnston would be out for but admitted his side were battling with injuries in their outside backs.
"We're a little bit under the pump at the moment with Greg Inglis and Rob Jennings and Campbell Graham all injured and now Alex," Seibold said.
"Adam Doueihi is included as well, he's out for the year. I was really happy with our depth.
"(Fill-in fullback Dane Gagai) hasn't done any reps the whole season at fullback. Young Tyrell Fuimaono, we pulled him up two days ago, hasn't trained with us for months, for him to do a good job like he did on Latrell Mitchell. You guys like at the result, I look at the effort."
Skipper Inglis is expected to return from a broken thumb against Brisbane next week but Seibold said he was no certainty.