Match ends, Barnsley 0, Middlesbrough 2.
Jelle Vossen's second-half strike put Middlesbrough on the way to a place in round four of the FA Cup at the expense of Barnsley at Oakwell.
The Belgian fired home on his left foot from Patrick Bamford's pass to break the hosts' resistance.
Boro's Adam Clayton was sent off for two bookable offences but Daniel Ayala's late headed goal from a corner eased any lingering nerves.
Conor Hourihane's shot saved by Tomas Mejias was Barnsley's best chance.
Middlesbrough, who relegated the Tykes to League One with a 3-1 victory at The Riverside in April 2014, move into the fourth round for the third season in a row.
|Barnsley tough to break down|
|Jelle Vossen's goal was the first conceded by Barnsley in the FA Cup this season after three clean sheets.|
|It was Barnsley's second defeat in their last seven home games against Middlesbrough in all competitions.|
Kick-off was delayed for 10 minutes by a gas leak, and the first activity of the game saw Boro's Rhys Williams withdrawn on a stretcher inside two minutes to be replaced by Milos Veljkovic.
The away side weathered that loss but failed to prise open the Tykes rearguard, with goalkeeper Ross Turnbull in particular denying Spanish striker Kike on several occasions.
Having edged the first period, Boro eventually made a breakthrough when Vossen finished off Bamford's pass, capitalising on a Barnsley error to open the scoring with a left-footed shot.
Turnbull continued to prove a difficult opponent, denying Kike, who was eventually replaced by Adam Reach, while Leroy Lita shot into the side netting on a rare attacking foray for the Tykes.
Clayton's dismissal for two fouls on Lita seemed to lift the home side, with Mejias tipping over Hourihane's strike, but Ayala's powerful header ended any hopes of a cup upset.
Middlesbrough coach Aitor Karanka: "The main thing is to get through so the work is done. It wasn't easy because when we lost Clayton it was a different game
"I'd have been happier if we'd scored our chances. We have to improve and keep concentrating.
"We had five or six great chances and we had to score them because we could have been four or five up at half-time. If we'd have scored earlier it would have been different, but the job is done."
Barnsley manager Danny Wilson: "Of course I'm disappointed. We'd set a certain game-plan up to frustrate them because they're a very good side.
"They had some chances in the first half and there were a couple of good saves from Ross [Turnbull], but we did stifle them.
"In the second half, the disappointing thing from my point of view is that the two goals we did concede were sloppy."
- 4BerrySubstituted forBoakye-Yiadomat 82'minutes
- 10HemmingsSubstituted forOatesat 69'minutes
- 25WilliamsSubstituted forVeljkovicat 5'minutes
- 8ClaytonBooked at 77mins
- 10TomlinSubstituted forLeadbitterat 80'minutes
- 9KikeSubstituted forReachat 66'minutes
- Dean Whitestone
- Shots on Target
Second Half ends, Barnsley 0, Middlesbrough 2.
Hand ball by Dale Jennings (Barnsley).
Foul by Milos Veljkovic (Middlesbrough).
Leroy Lita (Barnsley) wins a free kick in the attacking half.
Attempt missed. Jelle Vossen (Middlesbrough) left footed shot from outside the box is just a bit too high.
Goal! Barnsley 0, Middlesbrough 2. Daniel Ayala (Middlesbrough) header from the centre of the box to the bottom right corner. Assisted by Grant Leadbitter with a cross following a corner.
Corner, Middlesbrough. Conceded by Peter Ramage.
Substitution, Barnsley. Nana Boakye-Yiadom replaces Luke Berry.
Foul by Jelle Vossen (Middlesbrough).
Peter Ramage (Barnsley) wins a free kick on the left wing.
Substitution, Middlesbrough. Grant Leadbitter replaces Lee Tomlin.
Conor Hourihane (Barnsley) hits the bar with a left footed shot from outside the box from a direct free kick.
Second yellow card to Adam Clayton (Middlesbrough).
Leroy Lita (Barnsley) wins a free kick in the defensive half.
Foul by Adam Clayton (Middlesbrough).
Corner, Barnsley. Conceded by Milos Veljkovic.
Attempt blocked. Peter Ramage (Barnsley) header from the centre of the box is blocked.
Corner, Barnsley. Conceded by Adam Reach.
Attempt missed. James Husband (Middlesbrough) left footed shot from the left side of the box misses to the right following a corner.