Coronation Street fans were amazed on Wednesday night, as much-loved youngster Sam Blakeman's chess opponent was revealed to be someone close to home.
Sam actor Jude Riordan was joined by his real-life brother for the scenes, which he soon announced on his social media.
Zach played fellow youngster Oscar on the ITV soap, seemingly as a one-off, for the episode.
Things got awkward as the opponents went head-to-head in a game of chess, with Sam soon coming out on top.
But Oscar was a sore loser, as he failed to accept his loss and rejected Sam's attempts to shake hands - before storming out of the room.
It was after the episode though that Sam actor Jude revealed all on his real-life brother making a cameo alongside him.
Sharing a scene from the soap, Jude posted on Twitter : "When it was bring your Brother to work day. Sam smashed Oscar out of the bistro. BEST DAY so far @itvcorrie #bubblebrothers #samvoscar #corrie."
It was seemingly a Covid related decision, with Jude writing "bubble brothers" in the tweet - with the siblings obviously being in the same household.
Jude was thrilled to be alongside Zach, posting an image of them together on the set on his Instagram Story, writing: "Showing my brother the ropes."
He also revealed they were no stranger to going against each other in chess, telling a fan: "He plays a bit irl so we play together at home."
Viewers took to Twitter over the moment and Jude's confession that he and the actor playing Oscar were related in real life.
One fan said: "Good for you, nice to see Zach have a small part in your corrie experience."
Another said: "Didn't realise that was your real brother @JudeRiordan," as a third said: "Wait…that’s your brother?"
A fourth viewer commented: "wow how lovely!! I didnt catch all the scene but saw him looking a bit intense and not sure if he actually spoke in the end haha aww fab having a scene together playing Chess Rivals!! Will have to watch again on Catchup."
The comments kept coming too, with a fifth viewer tweeting: "So glad Sam won yippee! Didn't realise that was your brother how cool is that taken your brother to work," and another adding: "Oh Cool your real life brother?."
Got any theories or thoughts on the storyline? Let us know in the comments section below.
Coronation Street airs Mondays, Wednesdays and Fridays at 8pm on ITV.