Beat Kolkata Knight Riders by a good margin and end up with 15 points!
Now pray that Chennai Super Kings beat Kings XI Punjab so that Kings XI Punjab remain at 14 points. This way Rajasthan Royals can get the 4th spot on the table, while Deccan Chargers and Royal Challengers Bangalore will have to battle it out between themselves for the 3rd spot (with one of them ending with 16 points and the other with 14 points).
Given Rajasthan Royals win their match and Kings XI Punjab beat Chennai Super Kings in the following match, Chennai can still make it to the semifinals by kicking out Rajasthan Royals because they would know (even if they lose the match!) by what margin they should manage their run rate so that they could still beat Rajasthan Royals on the net run rate factor.
Bottom-line: Beat Kolkata Knight Riders and keep praying that Chennai Super Kings win their match against Kings XI Punjab!