An expansive South Sydney have made light work of a poor Newcastle 50-10 at Barlow Park in Cairns to move to second on the NRL ladder.

Rookie winger Alex Johnston scored a hat-trick of tries in the Rabbitohs’ biggest-ever win over Newcastle.

With Sam Burgess and captain John Sutton sidelined and Greg Inglis captaining the side for the first time, the Rabbitohs laid on five first-half tries to race to a 26-0 lead at the break.

Kirisome Auva’a, Lote Tuqiri, Tom Burgess, Dylan Walker and Chris McQueen all crossed for four-pointers in an opening stanza completely dominated by the Rabbitohs, who took their round-21 home game to the North Queensland city.

When Inglis scored just after the interval the match was over as a contest.

In front of 11,570 fans, the Knights were a shadow of the side which produced one of the upsets of the season over premiers the Sydney Roosters last Friday night.

Missing Jarrod Mullen, James McManus, Akuila Uate and Darius Boyd, the Knights brought some respectability to the scoreline with efforts to Jake Mamo in the 50th minute in the steamy conditions and Adam Clydsdale two minutes later.

It was all Souths again after that, as Johnston scored three tries in 16 minutes before Auva’a crossed for his second as the Rabbitohs notched their half century.

Rabbitohs rake Issac Luke also starred for the Rabbitohs in a man-of-the-match effort.

The victory puts the Rabbitohs behind premiership frontrunners Manly, and equal with Penrith but ahead on for-and-against.

Souths face the Sea Eagles in a top-of-the-table clash at the SCG on Friday night.

The loss leaves the Knights two points ahead of last-placed Cronulla.