Daniel Ricciardo will have a new teammate at next week's Spanish Formula One Grand Prix after Red Bull dumped Daniil Kvyat.
The team on Thursday announced the shock switch, with Toro Rosso driver Max Verstappen replacing Kvyat - who will re-join sister outfit Toro Rosso.
It follows Kvyat's crashes in Sunday's Russian Grand Prix, which led to Sebastian Vettel retiring from the race and ruined Ricciardo's chances of a decent result.
"Max has proven to be an outstanding young talent," Red Bull boss Christian Horner said.
"His performance at Toro Rosso has been impressive so far and we are pleased to give him the opportunity to drive for Red Bull Racing.
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"We are in the unique position to have all four drivers across Red Bull Racing and Toro Rosso under long-term contracts with Red Bull, so we have the flexibility to move them between the two teams.
"Dani will be able to continue his development at Toro Rosso, in a team that he is familiar with, giving him the chance to regain his form and show his potential."
Toro Rosso principal Franz Tost said they were "more than happy" to have Kvyat back.
Verstappen, the 2015 rookie of the year, is considered a champion of the future. Red Bull, determined to stave off interest from rivals, had been expected to promote him anyway at the end of the season.
Verstappen hailed his promotion as "an amazing opportunity", but Kvyat's demotion still came as shock even in a sport not known for second chances.
"Really? one bad race and Kyvat's dropped, what about the podium in the previous race? #Shortmemories," commented McLaren's Jenson Button on Twitter.
The only Russian on the starting grid, Kvyat has plenty of admirers but has also become embroiled in controversy.
He has clashed twice in two races with Ferrari's Vettel, the four-time world champion whose place he took at Red Bull, and has struggled to match Ricciardo's pace.
Vettel branded him a 'madman' in China last month for an overtake at the start that triggered a collision between the Ferraris.
Kvyat was named driver of the day after finishing third in that race, but he had no defenders after colliding twice with Vettel in Sochi last weekend in an accident that also destroyed Ricciardo's race.
