Middlesbrough left it late to consign Championship leaders Leicester City to a second successive defeat, courtesy of Sam Greenwood's stunning free-kick.
Leicester went close to taking a first-half lead first through Kiernan Dewsbury-Hall's header and Ricardo Pereira's shot was well blocked by the hosts.
Dael Fry almost put Boro in front at the break when he headed goalbound at the near post but the Foxes scrambled to keep his effort out of the net.
Boro eventually scored an 83rd-minute winner in impressive fashion as Greenwood whipped a free-kick into the top corner from long range.
The result means Leicester head into the November international break still top of the table, but only on goal difference from Ipswich Town, following their win over Swansea City.
Boro move up to 10th by virtue of their victory and are now two points outside the play-off places after sealing a first league victory against Leicester since March 2002.
Greenwood's strike continued his fine form for Boro of late as the Leeds loanee scored for the fourth time in his past six games for the club.
It was a frustrating afternoon for Leicester, who lost to Leeds last in their previous game, but dominated possession at the Riverside and registered more shots than their opponents, only for Greenwood's moment of brilliance to prove decisive.
Middlesbrough boss Michael Carrick:
"It was a big win. They are a really good team and we knew that.
"Individually, collectively, how they're coached, they're a very good team and it's not an accident that they are where they are in the league.
"We showed a different side to ourselves today with a lot of the out-of-possession work. It was really good pressing and really good defensively. They test you, you have to close certain spaces for the whole game, you have to concentrate for the whole game and that was a major factor.
"The boys got the game plan off to a tee and actually, the few chances we did give away were from us giving the ball away, which we don't normally do. That's one of those things though. It was an immense effort and I'm so proud of the boys."
Leicester City manager Enzo Maresca:
"I think I have been quite clear, we created many chances and many situations where we should score but when you miss, miss, miss and they score a fantastic goal, that's football.
"It's a moment where you create but don't take your chance and the opposite, they score a fantastic goal. It is what it is.
"To be honest I thought we were in control of the game, created five or six clear chances and many situations where we missed the last pass.
"The players are annoyed because we lost and it's normal to be like that."