Boro may have made it back-to-back home wins by beating Cardiff City at the Riverside on Tuesday, but the 2-1 success was tinged with disappointment for the defence after conceding for the first time in 581 minutes.
When Kenwyne Jones headed home in the 86th minute, it was the first time the best defence in the Championship had been breached since Jay Tabb scored a rare header for Ipswich against Boro back on December 20, a full month ago.
And defender Ben Gibson believes the disappointment within the Boro dressing room, despite emerging victorious, is testament to standards the team set themselves and are hoping to achieve this season.
"We're actually really disappointed as a defensive unit," said Gibson.
"Still though, we were going to concede at some point - that was inevitable - the main thing was that we got the three points.
"Dimi was really disappointed - because we don't concede many goals, but that's good, it just shows the marker and the high standards we set ourselves.
"We want to stick to those high standards and we don't think we should be conceding goals.
"We've got good players and it's a matter of concentration so we're disappointed, but we got the three points and the job done."
Aitor Karanka's men endured a frustrating first period against a Cardiff side that looked to have been set up to nullify any creativity in the Boro engine room.
The second half told a different story though, as Boro broke the deadlock through Patrick Bamford before Lee Tomlin slotted home his third goal in two games.
And Gibson said despite it not being the most enthralling of games, the team had three points in the bag and it was a case of job done.
"Getting three points isn't always going to be pretty and we really ground it out on Tuesday," he said.
"Cardiff came here with a game plan to stop us playing and I thought they did that really well, especially in the first half.
"But the important thing was to get the three points, we've got that and it wasn't pretty, but we're one point off the top now and we're slowly getting there.
"They stood on us to stop us playing out from the 'keeper. They really ratted around us and put us under pressure well, we had to turn them a lot and make it a 50/50 long ball game which we don't want, but it happened.
"I think we dealt with it well and second half they couldn't keep that work rate up so we got our foot on the ball and played it around a lot better."
Bournemouth fell to a 1-0 defeat at the hands of Leeds United on Tuesday night, meaning that with the three points, Boro moved to just one point off top spot - something Gibson was delighted about.
He said: "I was still on the pitch when I heard the Leeds result and I think there was a few fist pumps going around, but we really only need to concentrate on ourselves.
"There's a long way to go though and it's in our own hands. As long as you win your games it doesn't really matter what anyone else does, we're in touching distance so we only need to look at ourselves."