Neil Lennon was grim-faced as he walked up the tunnel, his mood darkened as much by the nature of this defeat as its consequences. Something was surrendered at Tynecastle, not only ground to Rangers in the title race, but also Celtic's sense of themselves as a commanding, assertive team.
The weekend's results defined what currently separates the two Old Firm sides: Rangers struggled against Hibernian on Saturday but still found a way to win 1-0; against a resilient Hearts, Celtic's frailties condemned them to a 2-0 loss. It was self-inflicted, since the goals were conceded cheaply and the team lost its spirit when Kris Commons was sent off.
Rangers are now 10 points ahead of third-placed Celtic in the Scottish Premier League, although Lennon's side have one game in hand. The break for international fixtures will leave the Celtic manager brooding on the flaws of his team.
"One player lost his discipline, but others then let their heads go down," Lennon said. "There's a few players who need to look at themselves."
There were scars left from the last meeting of these two teams at Tynecastle, on a night when a Hearts fan leapt from the main stand and threw himself at Lennon. The two sets of fans traded insults – the visitors sung about the IRA and the home fans chanted the name of John Wilson, the Hearts supporter who went for Lennon in that last game at Tynecastle.
The players had to be relentless – the occasion demanded it. Ryan Stevenson's diving header was tipped away by Fraser Forster, the Celtic goalkeeper, and David Templeton's flick bounced off the upright, but there was no sense of either side being in command of their nerves or composure. Celtic, too, created a couple of openings – Mohamed Bangura's header was saved by Jamie MacDonald, then Commons failed to beat the Hearts goalkeeper from close range. The players could only try to survive the frenzy.
In the end, Celtic's defenders could not. Six minutes into the second half, Jamie Hamill's cross fell to Rudi Skacel. The midfielder was being marked by Adam Matthews but still connected with a shot that flew past Forster. The goal seemed to agitate Celtic and when Commons lost control of the ball in midfield, he reacted impetuously and hurled himself into a tackle on Adrian Mrowiec that brought a red card.
When another speculative long ball caught Celtic's defenders unawares, Templeton back-heeled the ball from the byline to Ryan Stevenson, who fired it into the net. Hearts deserved their victory, for the tenacity of their approach. "We were up for the game," Gary Locke, the Hearts coach, said. "Now we need to build on it."
Hearts (4-5-1) MacDonald; Grainger, Webster, Zaliukas, Hamill; Jonsson, Black (Smith, 88), Templeton (Novikovas, 84), Stevenson, Skacel (Obua, 77); Mrowiec. Substitutes not used Balogh (gk), Elliott, McGowan, Robinson.
Celtic (4-4-2) Forster; El Kaddouril (McCourt, 79), Majstorovic, Mulgrew, Matthews (Wilson, 73); Ki Sung-Yeung, Wanyama, Bangura (Stokes, 59), Commons; Forrest, Hooper. Substitutes not used Zaluska, Samaras, Rogne, Slane.
Booked: Hearts Black, Skacel. Celtic Sung-Yeung.
Sent off: Celtic Commons (65).
Referee C Thomson (Renfrewshire).