Match ends, Middlesbrough 1, Accrington Stanley 0.
Stewart Downing's superb strike sent Middlesbrough through to the FA Cup fifth round with victory over League Two strugglers Accrington Stanley.
The hosts wasted numerous chances at the Riverside before Downing fired a left-footed shot into the top corner from 25 yards in the 69th minute.
Substitute Cristhian Stuani missed an open goal in added time.
Sean McConville went closest for Stanley, who are 20th in League Two, but they could not force an equaliser.
A nervy Boro had failed to capitalise on their dominance until Downing's goal, with Patrick Bamford missing two clear chances from close range on his first start for the club since joining from Chelsea.
Stanley's Sean Clare forced Dimitrios Konstantopoulos into a solid save in the first half, before McConville headed wide when unmarked on 83 minutes.
The visitors rarely threatened otherwise, with Marek Rodak keeping them in contention, making fine saves to deny Rudy Gestede and Adama Traore, the latter's effort falling to Stuani, who shot high over the bar with Rodak off his line.
Defeat means Stanley are yet to progress beyond the fourth round of the FA Cup, while Aitor Karanka's Boro secured their second win in five games in 2017, both in this competition.
Middlesbrough manager Aitor Karanka said: "The most important thing with these games is to just get through to the next round - we had chances to score more but sometimes it's difficult against these sides.
"Accrington Stanley were really organised and kept fighting to the end so I'm really pleased.
"Stewart Downing deserved to score, it was an amazing goal. I told him at half-time that he was one of the best players on the pitch but to score a goal is always best."
Accrington Stanley manager John Coleman said: "A lot of other club have played their kids - we can't ask Middlesbrough to play a weakened side so it's a testament to how well we've played that it was only 1-0.
"The financial aspect is great so a replay would've been fantastic.
"But now we've got to show the same heart and spirit in every league game from now until the end of the season."
Middlesbrough face West Brom in the Premier League at the Riverside on Tuesday. Accrington Stanley host fellow strugglers Notts County at the Crown Ground on Saturday, 4 February.
- 3FriendSubstituted forFryat 9'minutes
- 6GibsonBooked at 90mins
- 2da Silva
- 11FischerSubstituted forTraoréat 61'minutes
- 8ClaytonBooked at 81mins
- 7LeadbitterBooked at 64mins
- 19DowningBooked at 88mins
- 20BamfordSubstituted forStuaniat 70'minutes
- 14de Roon
- 32RodgersBooked at 90mins
- 5BecklesSubstituted forGornellat 90'minutes
- 4DaviesSubstituted forClarkat 74'minutes
- 15ClareBooked at 85mins
- 28ConneelyBooked at 14mins
- 14BocoSubstituted forMcCartanat 74'minutes
- Anthony Taylor
- Shots on Target
Second Half ends, Middlesbrough 1, Accrington Stanley 0.
Corner, Middlesbrough. Conceded by Jordan Clark.
Harvey Rodgers (Accrington Stanley) is shown the yellow card.
Adam Clayton (Middlesbrough) wins a free kick in the defensive half.
Foul by Harvey Rodgers (Accrington Stanley).
Attempt saved. Jordan Clark (Accrington Stanley) right footed shot from outside the box is saved in the top centre of the goal.
Ben Gibson (Middlesbrough) is shown the yellow card for a bad foul.
Shay McCartan (Accrington Stanley) wins a free kick in the defensive half.
Foul by Ben Gibson (Middlesbrough).
Attempt missed. Cristhian Stuani (Middlesbrough) right footed shot from the centre of the box is just a bit too high.
Attempt saved. Adama Traoré (Middlesbrough) right footed shot from the centre of the box is saved in the centre of the goal.
Substitution, Accrington Stanley. Terry Gornell replaces Omar Beckles.
Corner, Middlesbrough. Conceded by Marek Rodak.
Attempt saved. Cristhian Stuani (Middlesbrough) right footed shot from the right side of the box is saved in the bottom right corner.
Stewart Downing (Middlesbrough) is shown the yellow card for a bad foul.
Attempt missed. Adama Traoré (Middlesbrough) right footed shot from outside the box misses to the right.
Attempt blocked. Billy Kee (Accrington Stanley) right footed shot from the centre of the box is blocked.
Sean Clare (Accrington Stanley) is shown the yellow card for a bad foul.
Cristhian Stuani (Middlesbrough) wins a free kick in the attacking half.