There is a 24 hour cool-down period where the 3rd and further attack will go into +1 points. There is also much shorter 2 minute rematch counter that prevents you fighting someone in a shorter amount of time. Basically, what could happen is, for example:
attack 9:15 AM pervious day
attack 9:17 AM pervious day
attack 9:14 AM current day (+1 since it's 3rd attack in 24 hours)
9:15 AM (got timer)
attack 9:17 AM current day (full point, 2nd within 24 hour)
attack 3,4 of current day (+1, unfortunately the penalized battle count as well)
Just make sure 24 full hours passed and you should be fine, but you really shouldn't be farming points from one specific player to start with.