Definitely true! If you have one paper in top tier conference, you most probably get admitted in top school.
In my case, I haven't got MS yet. After my undergraduate, I spend 2 years researching to strengthen my profile. I have 11 publications; half of them are national, the rest are international, but in low tier conference (which I am not aware of their quality before). Despite the fact that my GPA is 4.0, and I am valedictorian (ranked 1/3000), I got rejection from Cornell, though.