Will Harrison nailed a drop goal in extra time as the Waratahs snapped a five-match losing streak to beat the Crusaders in a 43-40 thriller Friday that saw the lead change 12 times.
The Crusaders' Christian Lio-Willie crossed for a try in the 78th minute to seemingly kill off the 'Tahs hopes in a see-sawing clash at Sydney's Allianz Stadium.
But Johnny McNicoll conceded a penalty in the dying seconds and Harrison converted a pressure penalty after the final hooter to level the scores at 40-40.
It sent the match into a golden point scenario where Harrison, who until recently had been out of the game for nearly two years with injury, was again the hero with a drop kick two minutes into extra-time.
"It's a great feeling," said Waratahs skipper Jake Gordon.
"We've been close in a lot of games and it feels extra special to close that one out.
"I just thought throughout the night our energy was exceptional and to see Harro (Harrison) step up after such a long time out was very special."
While victory got the Waratahs' Super Rugby campaign back on track, it halted the Crusaders' revival after they beat the Chiefs a fortnight ago to halt a five-match losing run.
Super Rugby champions for the past seven years, it was the New Zealand side's first back-to-back defeat against Australian opposition since 2015.
In the earlier match at Whangarei, Moana Pasifika's William Havili banked a last-gasp converted try to seal a 17-14 win over an ill-disciplined Reds, who had Tate McDermott and Fraser McReight sent off.
Until then, the Reds had been the only Super Rugby team not to receive a red or yellow card this season.
Moana raced 10-0 clear with the competition's record-try scorer Julian Savea adding another to his collection.
But the Reds battled back and led 14-10 with five minutes on the clock, only for Havili to shake off two tackles and cross for the winning try with a minute left.
"Real happy after the last three weeks, we know we haven't been putting our best foot forward," said Tonga fly-half Havili after Moana ended a three-game losing streak.
"We made it hard for ourselves tonight, and it means a lot. We've talked a lot about belief during the week, that we're good enough on our day."