Joe Stimson's late try snatched a 16-13 victory over Sydney Roosters which all but wrapped up the minor premiership for Melbourne Storm, while Penrith Panthers are up to sixth in the NRL after fighting back to beat North Queensland Cowboys.
A Luke Keary drop goal seven minutes from time put the third-placed Roosters in front for the first time in a pulsating contest at AAMI Park, but there was a final twist.
Second row Stimson proved to be the Storm's match-winner, crashing over with only three minutes remaining after passing a concussion test to put the leaders six points clear with only three rounds to play.
Melbourne started with gusto, scoring 10 points without reply courtesy of a controversial penalty try, awarded when Latrell Mitchell impeded Suliasi Vunivalu as he chased Cooper Cronk's kick, and six points from the boot of Cameron Smith.
Keary dotted down for a converted try 10 minutes prior to the interval and the Roosters were level midway through the second half when Mitchell Aubusson crashed his way over, Mitchell adding the extras following a Smith penalty.
Five-eighth Keary showed great composure to send a drop goal sailing through the posts in a tense finale, but it was Stimson who had the final say, taking a pass from Cronk to power his way over.
Nathan Cleary was in-form Penrith's match-winner at Pepper Stadium, scoring a second-half double and landing four conversions as they beat the injury-hit Cowboys 24-16.
North Queensland led 16-6 in the second half courtesy of four-pointers from Kane Linnett, Michael Morgan and Jason Taumalolo, but Clearly struck twice either side from a try from former Cowboy James Tamou as the Panthers stretched their winning run to six matches.
Morgan (concussion) and Justin O'Neill (dislocated elbow) left the field in the first half on a night which saw the Cowboys drop to eighth.
St George Illawarra Dragons are just outside the top eight after Kurt Mann, Jason Nightingale and Cameron McInnes scored two tries apiece in a 42-16 drubbing of Gold Coast Titans.