Greater Western Sydney have stormed into the AFL's top eight for the first time since early May, edging Hawthorn by 11 points at Spotless Stadium.
GWS key forward Jon Patton largely struggled on Saturday night, copping a painful blow to the knee during a ruck contest, registering three behinds and putting another set shot out on the full.
But the former No.1 draft pick stood up when it counted most, booting the sealer from a difficult position after he was awarded a free kick with a tick under four minutes remaining.
"That was a big kick," GWS coach Leon Cameron said of Patton's composure.
"A lot of pressure.
"There's a lot of doubt, a lot of demons in your head from missing a number of goals ... and a couple of dropped marks, where it probably would have been an opportunity to score."
Hawthorn ball magnet Tom Mitchell had a game-high 36 disposals, while GWS co-captains Callan Ward and Phil Davis starred to help their side prevail 13.17 (95) to 13.6 (84).
The result rocketed the Giants, who slipped out of the top eight during a four-match losing streak, to sixth on the ladder.
The expansion club have won four on the trot and next tackle West Coast, Richmond and Port Adelaide in a challenging stretch that has the potential to make or break their campaign.
GWS won clearances 51-28 and had 53 more contested possessions than Hawthorn but couldn't put the Hawks away until late in the final quarter.
"We lacked some of the polish of GWS .. the scoreboard flattered us a little bit," Hawthorn coach Alastair Clarkson said.
The Giants snatched a 24-point lead after their most productive first quarter of the year, overwhelming the Hawks with frenetic pressure and frantic ball movement while kicking 5.3 (33).
The visitors reduced the margin to a single point during the third term, aided by the hosts' inaccuracy, but GWS rallied with three quick goals before three quarter-time.
The Giants' buffer was cut to five points early in the final term but Lachie Whitfield and Patton responded with clutch goals when the game was on the line.
"The easy thing is for players to panic," Cameron said.
"Every time they came at us, we found a way."
Patton loomed as the man most likely to fill the immense void left by fellow foundation Giant Jeremy Cameron, who sat out the first of five games he'll miss through suspension.
Instead, returning ruckman Rory Lobb booted three goals in the lopsided first term.
But Lobb was one of many forwards responsible for the home side's inaccurate haul of 1.8 in the second term, with the sole goal coming courtesy of a contentious free kick to Harry Himmelberg.
"That's almost a Rancey (Alex Rance) dive," Hawks defender Ben Stratton fumed to the umpire.
Hawthorn's Jack Gunston was a late scratching because of a corked calf and Will Langford suffered a finger injury.