Fresh from a training session at Rockliffe this afternoon Boro set about their penultimate pre-season friendly in determined fashion.
A powerful run on the break down the left from Yanic Wildschut had the Barnsley defence stretched in the opening minutes. His cross flew untouched across the face of goal but the start was encouraging.
Fabbrini wriggled his way into a shooting position 20 yards from goal and was only just off target in Boro's next attack.
Played at a higher tempo than Saturday's game at Doncaster, the game was not short of a hefty challenge or two with both sides determined to get as much as they could from it.
Boro were dealt a blow with 24 minutes played when Ben Gibson pulled up sharply after clearing, immediately feeling his hamstring. No chances were taken and after a very brief assessment he walked out of the game to be replaced by Adam Jackson.
Fabbrini had been the subject of some attention through most of the, shirking nothing and happy to mix it. But both he and Ben Pearson overstepped the mark in the closing minutes of the first half, both shown the yellow card after a challenge on the Italian brought a reaction from the Boro player and subsequent reaction from the Barnsley man with others looking to be involved.
It took just 90 second half seconds for Boro to take the lead as Albert Adomah set up Kike who drilled a low, angled, shot past Christian Dibble from 10 yards.
Two minutes later Kike turned provider as he worked his way in from the right to set up Fabbrini. His shot was saved but Albert Adomah was on hand to tuck home the rebound from close range.
Well protected by the accomplished Academy centre-back pairing of Jackson and Dael Fry, Mejias didn't have much to do throughout the evening, but he was called into action nine minutes into the second half, falling away to his left to gather a low, angled, shot from Conor Wilkinson.
A few minutes later Josh Scowen worked his way into the box, forcing another save from the Spaniard.
Lewis Maloney has caught the eye in games this summer, building on an impressive season with Boro's U21s and he was again at the heart of many good things tonight.
He wasn't on the scoresheet though, unlike Albert Adomah who scored his second and Boro's third with 65 minutes placed as he cracked home from the edge of the penalty area. The goal came shortly after he had seen a volley tipped over when meeting a right-wing corner when Adam Reach saw a fierce 20-yard drive turned behind.
Not to be outdone Kike, playing with plenty confidence, added his second with 73 minutes played as a deft touch brought a Clayton pass under control a low shot bat Dibble.
A couple of minutes later Adomah was denied a hat-trick Dibble turned a close-range shot over the bar.
Scorers Kike 47, 73, Adomah 49, 65.
Boro: Mejias; Nsue, Fry, Gibson (Capt. to 25) (Jackson 25), Husband, Adomah, Maloney, Clayton (Capt from 25 to 75) (Carayol 75), Wildschut, Fabbrini (Reach 60), Kike (Forshaw 75). Subs: Konstantopoulos (gk), Ripley (gk); Ayala, Leadbitter, Tomlin, Kalas, Friend.
Barnsley: Dibble; Bree (Roberts 46), Mawson (Capt. to 87) (Wardle 87), Nyatanga (Holgate 46), Smith, Scowen, Pearson, Rothwell, Watkins, Wilkinson (Jackson 66), Phenix (Maris 57). Subs: Walton.
Referee: Darren England.
Barnsley Pearson, 41, pushing.
Boro Fabbrini 41, pushing.
Conditions: Sunshine and showers.
Attendance: 2,082 (328 Boro)