THERE was an FA Cup shock at the Riverside on Saturday – Middlesbrough scored three goals. In terms of surprises, it might not have been on a par with National League Lincoln City winning at Premier League Burnley, but in the context of the Teessiders’ struggles in front of goal this season, it still represented an unexpected turn of events.

True, they were only playing against a side sitting in 12th position in League One, and true, they needed to score three goals to win the game after conceding twice in the space of 60 second-half seconds as Oxford staged a stirring comeback befitting this most unpredictable of FA Cup campaigns.

But as they attempt to combine a push towards Wembley with an increasingly frantic battle to remain in the top-flight, it is nice to know that Boro have not completely abandoned the process of trying to put the ball in the net.

Aitor Karanka displayed some uncharacteristic tactical flexibility, pushing Grant Leadbitter forward to play alongside Stewart Downing in a tweaked 4-1-4-1 formation, and his side were a much more potent attacking force as a result.

They recorded more shots in the first 45 minutes than they had mustered in the whole of any other game this season, and finished with an impressive tally of seven efforts on target. Three went in, enabling them to equal their highest goalscoring performance of the season so far, with Cristhian Stuani’s 86th-minute winner securing a first appearance in the FA Cup quarter-finals since 2008.

Back then, Gareth Southgate’s side froze as they lost to Championship opposition in the shape of Cardiff City. This time around, Karanka and his players look much more capable of claiming a semi-final spot at Wembley.

“It’s exciting,” said Fabio da Silva, who has been a beneficiary of Karanka’s tendency to rotate his squad for the cup competitions, featuring in all three of Boro’s FA Cup games. “We are in the quarter-finals now, and only have one more game before we get a chance to go to Wembley.

“That’s always exciting, and it’s a massive opportunity for everybody at the club. To get to the quarter-finals is good, but to get to a semi-final at Wembley would obviously be even better.

“I have never played in an FA Cup final. I have been to a semi-final (with Manchester United), but we drew 0-0 against Everton and got knocked out on penalties. I have never been to the final, so that’s obviously something I would really love to do.

“It is a big opportunity with the way the cup is going, but this weekend just shows you can never take anything for granted. If the big teams are going out to the smaller teams, it is because the smaller teams have quality and are playing well enough to beat them. We know that is always possible, and we have had to make sure it hasn’t happened to us in the games we have played.”

Saturday’s game, kicking off less than an hour after Lincoln had produced one of the biggest FA Cup shocks for many a year, looked ripe for another upset. Oxford, backed by a vociferous away contingent of more than 3,500 travelling fans, had brushed aside Newcastle United in the previous round, so it was to Boro’s credit that their first-half attitude in particular was so professional and focused.

Sharp and incisive from the off, the Teessiders scored twice before the break, with Leadbitter converting from the penalty spot after Chris Maguire had bundled Downing to the ground, and Rudy Gestede claiming his first goal in a Boro shirt as he hooked home acrobatically after Adama Traore’s knock-down was deflected into his path.

Boro’s first-half attacking play was sharp and incisive, with Traore and Viktor Fischer causing a succession of problems down the flanks, and both Leadbitter and Downing repeatedly breaking into the box to ensure Gestede was not isolated.

Karanka will claim that such an approach is more dangerous in the Premier League, where teams are adept at causing damage on the break. The Boro boss likes to have the security of three sitting central midfielders in the league, even in games at the Riverside, but Saturday’s performance proved that a minor tactical tweak can have profound effects in terms of attacking capability. If nothing else, the quality of Boro’s forward play should help engender confidence ahead of this weekend’s pivotal trip to Palace.

“When I was at Manchester United, we always took a lot from our cup runs,” said Fabio. “We always felt that doing well in the cups would help us with what we were trying to do in the league. You always get confidence from winning, no matter what competition you are playing in.

“We won 3-2 here, in a really good game, and everyone should be excited about that and take confidence from it. It should help to drive everybody on. It can only give us more confidence for the Crystal Palace game. It is always good to win – it makes everyone feel good – and when you have a win like this, with a late goal, it can only be good for the games in the future.”

That Boro needed that late goal, though, was alarming. With a two-goal lead at the hour mark, the home side should have been home and hosed, but some poor decision-making allied to some more generally shaky defending enabled Oxford to haul themselves back into the game.

Bernardo Espinosa and Daniel Ayala were anything but convincing throughout, while Traore and Adam Clayton were both guilty of extreme sloppiness as Oxford scored two goals in the space of a minute.

Traore senselessly barged into Phil Edwards on the edge of his own area, enabling Maguire to chip home an excellent free-kick, and Clayton conceded possession in his own half to spark a move that ended with Antonio Martinez slamming home the rebound after Brad Guzan saved from Maguire.

Oxford came close to claiming a winner when Conor McAleny whistled a low shot past the post, but Karanka’s substitutions came up trumps as Boro settled things with four minutes left.

Fabio crossed from the left, a tumbling Alvaro Negredo flicked the ball into Stuani’s path, and the Uruguayan replacement slotted home from close range.

“When the game is 2-0, and you have chances to make it three or four but do not kill off the game, it makes things difficult for you,” said Fabio. “We made it hard for ourselves, but we have very good character in the team and we showed that to score the third. Our character came through for us in the end.”