Boro were far from the City slicker side that caused the FA Cup coupon-buster last week but the win at Brentford was just as important.
After a sluggish start Boro were under the cosh in a torrid first half and twice Dimi Konstantpoulos had to make good saves.
But they held on and snatched the lead against the run of play on the stroke of half-time as Patrick Bamford won a penalty and Grant Leadbitter stroked it home.
Boro grew in assurance after the break and created some good chances on the counter while digging deep at the back to hold on to a seventh clean sheet in eight games and move back within one point of the top.
Aitor Karanka made three changes from the side that won 2-0 at Manchester City in the FA Cup.
Dimi Konstantopoulos was back in goal in place of Tomas Meijas, Ryan Fredericks returned to the right-back slot after injury in place of Dean Whitehead and Kenneth Omeruo was at centre-back in the starting line-up with Daniel Ayala suspended.
New boy Adam Forshaw, signed for £2m from Wigan in midweek, was on the bench for the lunchtime televised clash against his former club.
Brentford carved out the first chance in the second minute as a quick passing movement took Gray to the edge of the box and when he rolled it inside Douglas drilled well wide.
Boro launched their first raid on four minutes as Ben Gibson knocked a quick ball down the left and Jelle Vossen fired a low cross towards the run of Patrick Bamford but the ball was slightly behind him and got stuck in his feet then his fumbled 10 yard shot was turned behind.
The corner was floated in by Grant Leadbitter but Albert Adomah fired well over on the half-volley then Boro twice cut down the left for Adomah to whip in crosses that were headed away.
Brentford responded with a good spell of pressure and went close on 10 minutes as Jota carried the ball through the middle then chipped into the box for unmarked Gray to put a header wide.
Then a minute later they won a free-kick as Omeruo clattered Pritchard as he tried to carve into the box from the right and he was lucky to escape a booking.
Then when the free-kick was played short and square to Jota he took a touch just inside the box and lashed a shot through the crowd that Konstantopoulos tipped over.
And from the resulting corner Brentford went closer still as defender Tarkowski put in a powerful downward header that Leadbitter blocked with his thigh at the far post.
On 16 minutes Omeruo was booked for a foul on Gray.
And as the pressure continued Brentford almost had the opener on 18 minutes as Dallas turned to find space on the left of the box and rifle in a low shot that sent Konstantopolous full length and although the ball skidded awkwardly he managed to push the ball onto the post and Gibson hooked away the rebound before Gray could pounce.
Boro broke out quickly on 23 minutes as Leadbitter sent Adomah down the left and when he drilled in a low cross towards Vossen a defender came sliding in to deflect behind for a corner.
But Brentford were on the attack again as a quick move found Pritchard just outside the box but Bamford had tracked back and got in a tackle that sent the shot looping up high and into the arms of the keeper.
On 27 minutes Adam Clayton was booked for a foul on Jota.
On 31 minutes Brentford's Diagouraga was booked for a foul on Adomah.
Boro carved forward on 35 minutes as Tomlin weaved to the byline before being tackled then Vossen threaded the loose ball into the box for Adomah to go sliding in and get a touch to spark a scramble and he took two swipes at the ball while on the ground before it was hooked away by a defender.
Then a Ryan Fredericks low cross from the right flashed across the face of goal and Adomah stretched but couldn't connect.
On 40 minutes Bamford was booked for tugging at Pritchard as he raced down the left.
Brentford were on the attack again on 42 minutes as Dallas got to the edge of the box then slotted into the path of Gray but Leadbitter got there first and turned it behind.
But Boro grabbed the lead against the run of play on 44 minutes as they won a penalty.
Gibson pushed a ball down the left for Bamford to push and chase into the box where he was up-ended by advancing keeper Button who was lucky to just get a yellow.
When the ref pointed to the spot GRANT LEADBITTER stepped up to stroke home his eighth penalty of the season.
HALF-TIME: BRENTFORD 0 BORO 1
Brentford were quickly on the attack after the break as a Dallas cross behind the defence found Gray in the box but the striker fired wide and the offside flag was up anyway.
Boro hit back as they twice won corners but from the first Vossen's glancing header was well saved then from the second the Belgian's flick on bounced just outside the far post.
Brentford went close to a leveller on 52 minutes as Friend tracked back Jota to concede a corner on the left and when it was floated to the far side of the crowd impressive Pritchard sent a volley whistling inches over the bar.
Boro were straight back on the attack as Tomlin slotted a diagonal pass to the left hand side the box for Bamford to touch inside his man then drill a low angled shot that the keeper fumbled around near post for a corner which was easily cleared.
Then Boro almost had a second goal on 57 minutes as Bamford steered a ball out to the left for Vossen to carry forward the drill a square low ball into the box and Adomah did burst clear of his man but his stabbed shot 10 yard shot flew a foot over the bar.
And a minute later in another sweeping move Adomah sent Vossen down the left to trick into the box then push a neat ball into the path of Leadbitter's darting run but he couldn't get a clean contact and could only guide it straight to the keeper.
Brentford hit back as first Douglas shot over from the edge of the box then a crisp passing move found the run of Gray into the box but his hurried snap-shot was straight at Konstantopoulos.
On 62 minutes Douglas was booked for a foul on Tomlin.
Brentford almost broke through on 64 minutes as Dallas and Pritchard combined then sent Gray into the box but Gibson bravely charged down his angled shot.
On 68 minutes new boy Forshaw came on for Adomah to jeers from his former fans.
Brentford were still having plenty of possession but their passes were starting to get ragged then twice Gray made good tricky runs only for Friend to stick with him tenaciously and block his final ball into the box.
On 76 minutes Brentford put on Long and Bonham for Gray and Diagouraga.
Boro threatened on 78 minutes as Vossen and Bamford picked their way into the box then it was laid back to Tomlin but his shot was deflected over then the resulting corner easily cleared.
And two minutes later Boro almost carved through again as Forshaw wriggled down the left and into the box to pick out the run of Tomlin but he fired over from 12 yards.
On 80 minutes Boro put Adam Reach on for Vossen.
Brentford won a corner on 83 minutes and when it dropped to the back stick Long stabbed it into the side-netting.
Boro then broke quickly as a ball over the top sent unmarked Bamford steaming forward before a very late offside flag went up.
On 87 minutes Boro put Kike on for Bamford and a minute later Brentford put Smith on for Dean.
On 90 minutes Kike was booked for preventing a free-kick being taken.
The game was stretched and scrappy in the five minutes added time and twice Boro had to scramble the ball out of the box then Omeruo needed to be sharp to chest an awkward ball back to Konstantopoulos.
Then right at the death a Pritchard cross from the right dropped to the back post for Douglas but Omeruo stretched to deflect it over the bar.
The from the resulting corner Konstantopoulos saved well from a stabbed Long shot.
BORO: Konstantopoulos, Fredericks, Omeruo, Gibson, Friend, Leadbitter, Clayton, Adomah (Forshaw 68), Tomlin, Vossen (Reach 80), Bamford (Kike 87) Subs: Mejias, Woodgate, Whitehead, Ledesma, Kike
BRENTFORD: Button, Odubajo Tarkowski, Dean (Smith 89), Bidwell, Diagouraga (Bongham 76), Douglas,, Dallas, Pritchard, Jota, Gray (Long, 76) Subs: Craig, Saunders, Toral, Yennaris.
Ref: Simon Hooper (Wiltshire)
Att: 11,853 (1,662 Boro fans)
