Hmm as mentioned before, if you beat a ninja aside from iruka, preferably their dps. Then his whole team will fall apart. With a healer and iruka he will seriously lack a form of damage and from here on out you can slowly close out the game. Keep in mind that the way your formation is set up is also important. If iruka has the 3rd or 4th move in his team and your main is in move 2 then you can probably trigger a chase combo before iruka interrupts your skill. The only reliable damage I see in your team for single target is triggering a chase combo. If they have a sasuke I ussually focus either the sasuke or the main down first.
It is also important to not suddenly switch targets half way, it will give the opponent too much time to strike back. Once you decide on a target to kill, keep focusing that target. If you switch target your basically giving away a round for free.