Despite claiming top spot on the NRL ladder, Melbourne coach Craig Bellamy has urged his players to improve if they hope to maintain their position over the final month of the season.
While Bellamy was full of praise for South Sydney following the Storm's 15-14 golden-point win on Saturday night, a lethargic first-half performance has him looking for answers.
"I'm not quite sure why we were flat," Bellamy said.
"We will have a chat to the players through their review and we might find a couple of things out.
"But we were pretty disappointed, especially in our execution and certainly in the way we defended tonight, to be quite honest."
Storm captain Cameron Smith also felt the side lacked energy in the opening half but relied on their goal-line defence to stay in the match.
"Souths could have quite easily had two or three more tries in that first half if it wasn't for our scrambling defence," Smith said.
"That's what kept us in the game and gave us an opportunity to win it at the end."
Smith's 39-metre penalty goal in the final minute levelled the scores before the skipper stepped up again in extra-time, slipping out of dummy-half to kick the winning field goal.
It was Smith's second game-winning field goal for the season, his first giving the Storm victory against the Cowboys in Round 10.
"Cooper (Cronk) had a shot earlier and had a fair bit of heat on him," Smith said.
"He mentioned to me when we got the ball back on those seven tackles that, if I saw the opportunity, to go out to the left side and have a crack."
Melbourne's next opponent is a red-hot Canberra outfit and the coach is expecting a difficult assignment in the nation's capital on Monday week.
"The Raiders are playing the house down at the moment," Bellamy said.
"It's going to be a real tough ask for us up there.
"We just need to get back to work this week, improve in a couple of areas and hopefully we can go up there and be competitive with them.