The crowd were on their feet after three minutes when Maloney marked his Roosters debut with a try.
However, the response from the Rabbitohs was swift, as man of the match Inglis blazed his way deep into Roosters territory before releasing Merritt with a bullet of a pass.
The prolific winger raced to the line for the 130th try in Souths colours.
That kick-started the Souths forwards into action and they were rewarded when Merritt doubled his tally on the half-hour mark.
A teasing bomb from Reynolds was flicked into the path of Inglis, who found Dylan Farrell in space and the young centre offloaded for Merritt to score.
The setback prompted Roosters coach Trent Robinson to throw Williams into the fray for the first time since his controversial exit from Canterbury in 2008.
The Kiwi was greeted with a some heated words from Burgess, who then ran straight over the Rugby World Cup winner, much to the delight of the Rabbitohs supporters.
Souths continued from where they left off at the break, dominating in attack as the Roosters ill-discipline continued to let them down in addition to a number of basic errors.
The arrival of giant George Burgess from the bench added some extra beef to the Souths go-forward and the younger brother of Sam showed his potential with some powerful runs with the ball.
Six minutes after the break the Englishman scored his first NRL try when he bulldozed his way under the posts to end the game as a contest.
Merritt scored his third on the hour with Inglis once again the instigator to add some extra gloss, before Williams, who was quietly effective in his 50 minutes on the pitch, hauled in a Frank-Paul Nuuausala pass to race under the posts.
Reynolds kicked four goals, with Maloney kicking one for the Roosters.
Jennings was put on report just before the interval for a high shot on Beau Champion as was Sam Burgess for a high shot on Pearce.
- AAP