South Sydney fought off a second half fightback from Penrith for a high-scoring 44-32 victory to remain unbeaten and join Melbourne at the top of Australia's National Rugby League on Sunday.
Penrith clawed back from 34-16 down at halftime to get within two points of the Rabbitohs with 10 minutes remaining.
But the Rabbitohs kicked clear with two late tries including the final four-pointer to winger Nathan Merritt, who scored a hat-trick in the 14-try thriller.
Melbourne Storm are the other unbeaten club following their 22-18 victory over Canterbury Bulldogs, the team they beat in the grand final for last season's NRL title.
Gold Coast Titans dug deep for a 16-14 win over Manly Sea Eagles to lie third on the NRL standings.
The match was locked at 14-14 after Manly scored three second-half tries before scrum-half Daly Cherry-Evans conceded a match-winning penalty late in the clash.
Cherry-Evans kicked a goal-line drop-out over the sideline and Aidan Sezer kicked the penalty goal from in front of the posts to clinch the Penrith victory.
A stout defensive display from the Sydney Roosters laid the foundation for an 8-0 win over Brisbane.
James Maloney scored all of the points, running in for the only try of the game on 30 minutes and then kicking a penalty goal midway through the second period.
Wests Tigers turned on the style, beating Parramatta 31-18 for their second straight victory.
Two first-half tries from Chris Lawrence and Blake Ayshford helped the Tigers open up an 18-0 lead after they dominated the opening 40 minutes.
Cronulla showed little to suggest they are a club in crisis with a comfortable 28-4 win over the New Zealand Warriors.
Coach Shane Flanagan was back at the helm after being stood down by the Sharks in light of the probe by the Australian Sports Anti-Doping Authority.
Newcastle Knights and North Queensland Cowboys complete the third round of matches on Monday.