Sydney Rugby Sevens fans warned to behave

AAP

Rugby fans have been warned to be on their best behaviour after more than 80 people were booted from the first day of the Rugby Sevens Series in Sydney.

Police and security staff kicked out 81 people from the two-day tournament on Saturday, with several fans banned and charged.

Tens of thousands of people are expected to attend the sold-out event at Allianz Stadium on Sunday.

Attendees have been warned to keep their drinking in check and forget about any plans to invade the pitch.