Penrith Panthers set a new club record with a ninth successive NRL win, though their 18-12 triumph over New Zealand Warriors was overshadowed by alleged racial abuse of Brent Naden.
Panthers winger Naden, who is an indigenous Australian, reported comments made from a section of the crowd that led to a small group of supporters being escorted from Central Coast Stadium.
The NRL are investigating the incident; acting CEO Andrew Abdo said in a statement that "decisive action" will be taken against anyone found guilty, while the governing body will offer support to those players involved.
Naden scored the opening try as Penrith maintained their impressive streak, Apisai Koroisau and Dylan Edwards also touching down as the leaders opened up a 16-6 advantage by half-time.
Patrick Herbert converted his own try as the Warriors fought hard in the second half, though the table-topping Panthers held on to make it nine in a row.
In Friday's other game, outgoing coach Paul McGregor enjoyed a successful farewell as St George Illawarra Dragons prevailed 14-12 against Parramatta Eels.
The Dragons announced this week that McGregor would be stepping down after the game at Bankwest Stadium, despite having over a year left to run on his contract. Dean Young is to take over on an interim basis.
His final outing in charge saw a victory secured thanks to a brace of tries from Mikaele Ravalawa, as well as six points from the boot of Zac Lomax.
Clinton Gutherson and Kane Evans touched down for the Eels, who missed the chance to go level on points with the second-placed Melbourne Storm in the ladder.