Hearts' European aspirations suffered a damaging blow in Lanarkshire as Hamilton Academical won with a solitary first-half strike.
Aaron McGowan's looping first-time finish settled this affair, the defender's first Accies goal giving his team three vital points in their quest to avoid relegation and ending Hearts' hopes of three successive victories. The Edinburgh club also lost ground on fourth-placed Kilmarnock in the Premiership table.
This game survived the inclement weather which claimed a number of matches around the country. However, it ended in frustration for the visitors. McGowan struck during an opening 45 minutes which Hamilton largely dominated. Hearts reacted after the break and introduced three strikers as substitutes but the equaliser remained elusive.
The travelling fans were unhappy at the end and made their feeling clear as they left the Hope CBD Stadium.
With striker David Vanecek and midfielder Peter Haring restored to the team, Hearts had a strong spine despite leaving Uche Ikpeazu on the substitutes' bench. Hamilton were without the former Tynecastle forward James Keatings due to an ankle injury sustained in training on Friday.
Vanecek quickly found himself embroiled in a physical contest against a three-man back line of Alex Gogic, Matt Kilgallon and Ziggy Gordon. The Czech wrestled as well as he could but conceded fouls at times attempting to win the ball. He looked keen to run in behind for through passes but most of his service landed in front of him with his back to goal.
Hearts cheaply conceded possession twice in the opening 15 minutes, which forced them to retreat against a team who like getting in about opposing defenders. The Hamilton striker Mickel Miller sprinted through to collect McGowan's lofted pass on 20 minutes but could only lift his finish over Zdenek Zlamal's goal.
Callumn Morrison then had a run and left-footed attempt at the opposite end which curled past the post. However, Hamilton were asserting themselves better than their guests. John Souttar blocked Scott Martin's strike from the edge of the penalty area, and Zlamal held a downward header by McGowan from Tony Andreu's corner.
The pressure yielded a deserved opening goal on 36 minutes. Hearts seemed to switch off as Accies moved down the left and Lennard Sowah, another of their ex-employees, delivered a deep cross. Opposite wing-back McGowan stretched out his right boot as he arrived at the back post to hook a looping finish high into the net, leaving Zlamal helpless.
Although they hadn't threatened much, Hearts came tantalisingly close to equalising moments before half-time. Vanecek controlled Morrison's driven ball into the penalty box and showed quick feet to dispatch it goalwards from 12 yards. The striker saw his attempt crash off the crossbar before Arnaud Djoum's headed rebound was cleared almost on the goal line by Gogic.
Vanecek was replaced at half-time by Ikpeazu, who had been given a rest after relentless action since returning from injury last month. Another striker, Aidan Keena, was introduced ten minutes after the break for Jake Mulraney, and then came Craig Wighton in place of right-back Jamie Brandon.
Hearts were deploying every available attacking weapon in search of an equaliser. From Ikpeazu's left-sided cross, Keena volleyed over the Hamilton crossbar on 70 minutes. Then came Ben Garuccio's delivery for Haring to head but Gordon was in place to deflect the ball out for a corner.
Ikpeazu's header from Morrison's cross was high, but wide areas continued to be Hearts' favoured route forward. They passed the ball well in spells and were camped in the home half right up until stoppage-time, only to be denied a point as they strive for the Europa League qualifying rounds.
Hamilton (3-4-1-2): Woods; Gogic, Kilgallon, Gordon; McGowan, MacKinnon, Martin (Imrie 90), Sowah; Andreu (Tshiembe (79); Oakley (McMillan 71), Miller. Unused subs: Fulton, L Smith, Boyd, Mimnaugh.
Hearts (4-3-3): Zlamal; Brandon (Wighton 66), Souttar, Berra, Garuccio; Haring, Djoum, Clare; Morrison, Vanecek (Ikpeazu 46), Mulraney (Keena 55). Unused subs: Doyle, Dikamona, Bozanic, Cochrane.
Referee: Willie Collum.