Dundee United arrested a two-game losing away run with a well-executed win at Tynecastle.
Robertson savours his opening strike at Tynecastle
Jordan Robertson fired home after 14 minutes to shock the hosts, and he added a second in the 25th, taking advantage of poor home defending.
Barry Robson netted a penalty as Calum Elliot and United keeper Grzegorz Szamotulski received late red cards.
Laryea Kingston clipped home a free kick in injury time but it was far too late as United eased to victory.
The outcome brought Hearts' recent run of good form to a shuddering halt, with questions to be asked of the shoddy defending by the men in maroon.
The Edinburgh club made three changes to the side which beat Falkirk in their last match for United's visit.
Lithuanian trio Tomas Kancelskis, Audrius Ksanavicius and Andrius Velicka dropped out and were replaced by Jose Goncalves, Christian Nade and Calum Elliot.
Ex-Hearts chief Craig Levein, meanwhile, made just one change to the team which defeated Motherwell 1-0 a fortnight ago, Steven Robb being replaced by 19-year-old Robertson.
United won 4-0 in their last visit to Gorgie, but this trip to the capital was anticipated to be a tough test.
Hearts carved out the first chance when Christian Nade cut in from the left flank but his shot was well held by Grzegorz Szamotulski at his near post.
However, the visitors response was to promptly shock the vast majority of 16,661 crowd with the opener.
With Marius Zaliukas' failing to clear the danger in the penalty area, Robertson, on a season-long loan from Sheffield United, spun and cleverly drove home a left foot shot, with the ball going in off the post.
Hearts, clearly shellshocked, attempted to recover, but the teenager silenced the home fans with a swift second.
Lee Wilkie won an aerial battle in the penalty area from Christian Kalvenes' free kick and Robertson was first to react.
Hearts' Christian Nade (left) and Lee Wilkie battle for possession
With the Jam Tarts defence once again lax, he fired the ball into the roof of the net to stun keeper Steve Banks.
Michael Stewart almost pulled a goal back at the other end, but the former Manchester United midfielder's shot was blocked by the scrum of United players who had retreated to the by-line.
With Hearts applying further pressure, Zaliukas had a shot cleared off the line by Morgaro Gomis, but the Tangerines retained their two-goal advantage at the break.
United has to marshall their resources as the second half progressed, as Hearts reacted in the best manner possible to the double blow with good possession.
Mauricio Pinilla was given an opportunity to impress in a maroon jersey for the first time since September last year, with Hearts fast running out of ideas.
Morgaro Gomis, meanwhile, was a composed presence for the Taysiders in a congested midfield, with United forced to work hard to hold on to their lead.
Hearts failed to create the sort of chances required to help them get back into the game.
Kingston did manage to drill a dangerous shot across the face of the goal, with the Ghanain playing a key role in the Jam Tarts' attempts to rescue the situation.
Hearts misery was completed with seconds remaining as Calum Elliot handled the ball on the goal line and the Scotland Under-21 youngster was summarily dismissed.
Robson crisply converted the spot kick, signalling the Hearts fans to depart Tynecastle in their droves.
Szamotulski, dramatically saw red with a late handball outside the penalty area, but it mattered little.
Kingston's set piece strike past substitute keeper Euan McLean was of no consequence in injury time, as United captured a morale-boosting three points.
Hearts: Banks, Neilson, Zaliukas, Berra, Goncalves (Ivaskevicius 87), Kingston, Stewart, Jonsson, Driver (Ksanavicius 46), Nade (Pinilla 61), Elliot. Subs Not Used: Kurskis, Tall, Karipidis, Palazuelos.
Sent Off: Elliot (89).
Goals: Kingston 90.
Dundee Utd: Szamotulski, Dillon, Wilkie, Dods, Kalvenes, Flood (McLean 90), Bauben, Robson, Gomis (Kerr 83), Hunt, Jordan Robertson (Robb 83). Subs Not Used: Daly, Cameron, Kenneth, Duff.
Sent Off: Szamotulski (90).
Booked: Wilkie, Jordan Robertson, Szamotulski.
Goals: Jordan Robertson 14, 25, Robson 89 pen
Ref: C Thomson