Believe me, this WILL take ages! (like, 40+ hours of gameplay). The quickest/easiest way is to NOT play a game on your account until you can play a 45+ rank, preferably a 50. If you play a 50 with an account that hasn't played a single game online, you will get it in 4 or 5 games. Seriously.
Believe me on this, I am the master of this game. (won 50 tournaments legit, first person to 1000.) And I didn't mean to sound boastful there :P
First legit 1000 in Rockstar Table Tennis
First person to have 1750 in three different games