Boro made a winning start on Spanish soil after goals from Albert Adomah, Adam Forshaw, and Kike proved enough to see off Leyton Orient in a behind-closed-doors friendly in Marbella.
Considering the searing heat, the tempo was quite surprising with both sides looking to move the ball and press in what Aitor Karanka had described as another training session for his players.
Karanka mixed his squad up with the youngsters benefiting from some experienced heads alongside them. Lewis Maloney partnered Grant Leadbitter in midfield and Dael Fry was alongside Dani Ayala at the back.
Both Emilio Nsue and Adomah sent shots wide early on, and Adomah had one cross saved after a stunning ball from Leadbitter.
At the other end, Ayala marshalled the defence well as Boro snuffed out Orient's forays forward.
As the half wore on, and after a water break, Boro applied more pressure with James Husband looking to overlap, Lee Tomlin looking to force his way through, and the lively Adomah venturing for an opening.
That breakthrough did come moments before the half-time whistle when Ayala sent a long pass forward and Adomah showed good to skill to control before flicking it beyond the reach of the Orient goalkeeper.
The second half started a similar tempo and after Kike had a penalty appeal waved away following great work by George Friend, the striker was again involved when Forshaw was on hand to stroke the ball home to double the advantage on 52 minutes.
Boro were good value for the advantage, although Dean Cox fired a warning shot with a well executed free-kick which Tomas Mejias did well to palm away. And, from the resultant corner, the Os pulled a goal back when a trialist converted from close range.
Despite conceding, Boro were soon controlling possession once again and Orient were forced into defending deeply and in numbers to snuff out any real threat.
But, there was still time for another goal, and Kike was rewarded for his persistence when he converted after more good work by Friend.
In the closing moments, the Spanish striker had another couple of opportunities, but he couldn't add to his tally.
Boro (1st half): Dimi, Nsue, Ayala, Fry, Husband, Leadbitter, Maloney, Adomah, Tomlin, Reach, Fewster.
Boro (2nd half): Mejias, Kalas, Burn, Jackson, Friend, Clayton, Forshaw, Carayol, Cooke, Wildschut, Kike.