The Sharks, who finished last in 2011, moved to third place on the NRL ladder following a compelling battle against the visiting Parramatta Eels.
Cronulla winger Stewart Mills scored the only try of the second half to give the Sharks a well-deserved victory after the teams had gone into halftime locked at 18-all.
Competition leaders Melbourne Storm remained unbeaten after seven rounds but not before surviving a stern challenge from the Canterbury Bulldogs.
The Storm relied on their superb defence to see off Canterbury, who were not helped by a number of unforced errors.
“It was the biggest test we’ve had all year,” Melbourne captain Cameron Smith said.
“They’ve got a big forward pack and they really worked us over through the middle.
“They used the ball really well between their forwards and asked us a lot of
questions with our defence.
“That’s why we won the game – look how many times we defended our tryline and had repeat sets there but it was a fantastic job defending our line and that’s why we won.”
Brisbane kept up the pressure on the Storm when they beat Canberra 30-6 in Brisbane to record their sixth win of the season, while the North Queensland Cowboys jumped to fourth in the table demolishing the Sydney Roosters 50-0.
Last year’s champions Manly suffered a shock 26-14 home loss to lowly Gold Coast.
However, 2011 runners-up New Zealand Warriors bounced back to form with an entertaining 44-22 win over the South Sydney Rabbitohs.
In other results, St George Illawarra beat Newcastle 12-4 and Wests Tigers thumped Penrith 30-0.