Aitor Karanka's first major signing of the close-season produced an encouraging display.
The £2.7million buy from Real Murcia converted a 15th-minute penalty after he was tripped inside the area trying to latch on to Richie Smallwood's through ball.
The Spaniard would have added to his three goals during pre-season had it not been for Josh Lillis in the Dale goal.
Before Kike scored, Adam Reach had given Boro the lead with a brilliant volley from the edge of the area.
Ian Henderson pulled a goal back for the Sky Bet League 1 side shortly before half-time, but Lee Tomlin restored the two-goal lead from the penalty spot after he was fouled inside the box.