Partizan Belgrade arrived at the Riverside Stadium with an unbeaten record over 25 matches of league and cup action.
Yet Boro shattered that record with a two-goal blast inside the opening 22 minutes.
Slovakian international Szilard Nemeth and Dutch international Joseph-Desire Job had publicly complained before the match about their lack first-team opportunities.
Manager Steve McClaren named both in his starting line-up and the strikers responded with a goal apiece.
Jimmy Floyd Hasselbaink and Mark Viduka will continue as McClaren's first-choice strikers but the England coach has the consolation of knowing squad members will not let him down.
Job gave Nemeth a scoring chance after ten minutes and the Slovakian kept his cool although there was a suspicion of offside.
Nemeth returned the favour shortly after with Job shooting home from just inside the penalty area.
Partizan showed a lack of attacking enterprise in the first-half and Middlesbrough remained in command before the break.
Surprisingly Stewart Downing, who has been tipped to win full honours for England, had a quiet game in the Middlesbrough attack.
Partizan showed much more enterprise after the interval and they began to stretch the Boro defence.
Skipper Sasa Ilic missed a great chance to reduce the arrears while Mark Schwarzer made a brilliant save from Albert Nadj shortly after.
James Morrison replaced former Arsenal star Ray Parlour and had the satisfaction of scoring in the final minute.
He cut in from the right to take his chance in style with a shot from outside the penalty area.
McClaren must be thrilled that Morrison looks like being another future star to roll off the assembly belt at the club's Academy.