It took just 20 minutes to kill off the Highlanders' Super Rugby campaign.
They had led 23-6 against the Waratahs in Sydney, but a 52nd-minute yellow card to winger Waisake Naholo opened the door for the home side - and they walked right through it.
The Waratahs scored three tries, all converted, in the time Naholo was off the pitch to jump out to a 27-23 lead, before No10 Bernard Foley added a penalty in the 71st minute.
"It was pretty tough going out there in the last 20 minutes watching it all slip away," Highlanders loose forward Elliot Dixon told Newstalk ZB's Martin Devlin. "When Waisake got yellow-carded it pretty much just swung."
Naholo was sent to the sin-bin for twice tackling prop Sekope Kepu high as he stormed into the Highlanders' 22.
A man down, the Highlanders shifted their defensive system, and cracks started to show. The Waratahs didn't miss them.
Dixon said the home side's backline did well to make the visitors pay when they had the opportunity.
"Israel [Folau] and Kurtley Beale, credit to them, they found a lot more holes in our defence."
When Naholo returned to the pitch the Highlanders were still well in the hunt, down by just four points. Even after Foley put the Waratahs ahead by seven, the Highlanders had their opportunities to tie the match up, especially when the Waratahs lost prop Paddy Ryan to a yellow card in the 74th minute.
But they were unable to capitalise.
"We were calm and collected," Dixon said of the Highlanders falling behind. "We knew we had the chance to win it; but when it came down to it, just the execution ... we just didn't execute like we should and would in a normal game to take it probably to overtime.
"As a player you build up to this point of the season and to have it let down like that it's pretty devastating for us."
With the win, the Waratahs booked a trip to battle the Lions in Johannesburg next weekend, after the Lions beat the Jaguares in their quarter-final.
In the other semifinal, the Hurricanes will make the short trip over Cook Strait to take on the Crusaders in Christchurch.