Rangers boss Mark Warburton admits he's never seen his side play worse than their shocking second-half collapse at Tynecastle, and expects a reaction from his players in the coming weeks.
Gers conceded three goals inside 14 minutes after the break as they allowed Hearts to run riot.
The 4-1 defeat in Gorgie was another painful lesson for Rangers from a turbulent campaign and Warburton confessed the performance was even bleaker than September's five-goal hammering by Celtic.
"We've just lost 4-1," said the former Brentford boss. "We're Rangers Football Club, we don't lose 4-1. We did tonight and I feel frustrated, absolutely.
"We weren't good enough second half. On Saturday against Motherwell, I thought it was as good as we've played in 18 months.
"Tonight, second half was as bad as we've played in 18 months if not the worst.
"I didn't see it coming. Nobody did, the players or staff. We all have bad days at the office, like last time we were here, but we thought we had learned from the first visit not to give the crowd anything.
"Then we gave away schoolboy errors at the start of each half. We have to be better than that.
"Players and staff are human and you are going to make human error but tonight we didn't get tight in the second-half, we didn't test the keeper, and generally it was way below the level we expect. We need to see a reaction."
Gers allowed Krystian Nowak to head the hosts ahead after just four minutes and while Emerson Hyndman - the only outfielder in blue to get pass marks - volleyed them level after 36 minutes, the Glasgow side fell apart after the interval.
Man-of-the-match Jamie Walker smashed home Hearts' second after Andy Halliday's slip four minutes into the second period before grabbing another after Don Cowie had tapped home the third.
The victory was a huge boost for Jambos boss Ian Cathro as he claimed just his third win since replacing Robbie Neilson.
His side - boosted by the tireless workrate added by new striker Isma Goncalves - never gave Gers a minute's peace.
The Gorgie boss said: "I'm pleased that a lot of people have been able to let out some of the frustrations they've been through in the more difficult moments we've experienced so far.
"What impressed me most about the performance was that it lasted for 90 minutes. That's important.
"Isma offers that tenacity, he attacks directly. He doesn't wait around, he goes and makes things happen. That's what we wanted in the squad. It was nice for him."