The Crows led by 23 points late in the second quarter of Saturday night's match, and they overcame Amartey's first blitzkrieg to still lead by 16 points late in the third.
But Amartey's heroics eventually proved too much to handle for the Crows as Sydney kicked the next 10 goals of the match to secure the 16.13 (109) to 10.7 (67) win.
The victory was Sydney's ninth on the trot, and lifted them three wins clear on top of the ladder with a 12-1 record.
Amartey also showed his marking abilities against the Crows in Adelaide. (Matt Turner/AAP PHOTOS)
Amartey didn't have a disposal to his name at quarter-time, but he kicked four goals in the second term and another four in the third to flip the match on its head.
He added another goal in the final term to finish with 9.1 from 10 disposals.
The 24-year-old's haul was the most by a Sydney player since Lance Franklin kicked 10 against Carlton in round 23, 2017.
Amartey's previous personal best was four goals, but his magical night against Adelaide boosted his season tally to 31 goals and has put him in the mix for the Coleman Medal.
Errol Gulden was also huge for Sydney with 35 disposals, 10 clearances, one goal and 766m gained, while Brodie Grundy racked up 31 possessions, nine clearances and 49 hit-outs.
Adelaide made the most of their chances in the opening term, kicking four goals to two to take an 11-point lead into the first change.
It marked the fourth consecutive match Sydney had trailed at quarter time, and the warning bells were ringing when a Brayden Cook volley put Adelaide ahead 45-22 with seven minutes remaining in the half.
Amartey had already kicked a goal from a strong mark earlier in the second term, but he was left frustrated time and again by Sydney's poor entries, which often favoured Adelaide's defenders.
When Sydney finally fixed up their flaws, Amartey cashed in with a three-goal burst in the final five minutes of the quarter.
The first of that flurry came via a set shot from a tight angle.
A contested mark with a little less than four minutes remaining set him up for another goal, and he ended the rampage with an acrobatic snap around his body.
Amartey entered the half-time break with 4.0 from four kicks, helping reduce the margin to four points.
The Crows kicked away again after the break, and with six minutes to go in the third quarter, Sydney were still yet to kick a goal for the term.
That all changed in the blink of the eye as the Swans slammed through six unanswered goals to finish the quarter, including four to Amartey.
A new career-high for Joel Amartey with his fifth!— AFL (@AFL) #AFLCrowsSwans pic.twitter.com/F55SzBd6YrJune 15, 2024
Most of Amartey's goals came from marks, with his efforts giving Sydney a 21-point lead at the final change.
Amartey took another strong mark midway through the final quarter to kick goal No.9 with 10 minutes remaining, but goal No.10 just eluded him.
10°C