Middlesbrough 0-2 Hull City
Aaron McLean and Nick Proschwitz scored either side of half-time to see Hull City past Middlesbrough.
The Premier League side were in front when McLean reacted to David Meyler's deflected shot to poke the ball past goalkeeper Dimi Konstantopoulos.
George Friend fired wide for the Championship side in the second half of a game of few real chances.
Proschwitz then turned home his second goal of the season from inside the area to seal Hull's place in the next round.
Middlesbrough, who reached the FA Cup final in 1997, came into the game with a decent record over Hull with seven wins in eight at the Riverside Stadium over the Tigers prior to this third-round clash.
Hull boss Steve Bruce made nine changes from their New Year's Day defeat by Liverpool owing to a heavy festive fixture load and a sickness bug in the camp.
That would have given Middlesbrough more confidence but it was one of those new faces who opened the scoring for the visitors.
A deflected shot from Meyler fell to McLean and he managed to poke the ball past Konstantopoulos in the 10th minute, just a day after returning from a loan spell at Birmingham.
After Friend's attempt, Marvin Emnes charged at the Hull defence and put a teasing ball low across goal but nobody was on hand for Middlesbrough to tap home.
Hull then sealed the game when a low ball in from George Boyd was turned home by Proschwitz, who readjusted to wrap his boot around the ball and find the net in the 61st minute.
Curtis Main headed into the side-netting Aitor Karanka's side late on but they could not muster a comeback.
Middlesbrough manager Aitor Karanka on Chelsea's Nigerian defender Kenneth Omeruo who is set to sign soon: "Jose [Mourinho] and I are friends, so always since I have arrived here it has been talked about. I said to him 'listen, can I take Michael Essien'. Maybe not, but me and the club are working to take players.
"I am happy [Omeruo] will come here to help us. I think that he will come until the end of the season."
Hull manager Steve Bruce: "There's a possibility Aaron McLean and Nick Proschwitz could both be gone before the fourth round because the transfer window is open.
"The thing is if you're a footballer and you're not playing every week you have a good to knock down my door, and I would be exactly the same.
"If there is a solution for both that is good for them and good for us then we'll listen to it. But they both reminded us of what decent players they are and took their chances very well."
- 11LedesmaSubstituted forAdomahat 45'minutes
- 7LeadbitterBooked at 83mins
- 10EmnesSubstituted forButterfieldat 83'minutes
- 14WilliamsBooked at 24minsSubstituted forJutkiewiczat 45'minutes
- 29QuinnSubstituted forJahraldo-Martinat 83'minutes
- 15McShaneSubstituted forChesterat 76'minutes
- 21McLeanSubstituted forElmohamadyat 80'minutes
- Kevin Friend
- Shots on Target