Ryan Bowman's header pushed Partick Thistle closer to the drop as they slumped to a 1-0 home defeat to Motherwell.
The striker was afforded space to head home David Tunrbull's free-kick from six yards on the hour mark and all but consign Thistle to a bottom-two finish in the Ladbrokes Premiership.
Alan Archibald's side are three points behind Hamilton with a game remaining but Accies have a 13-goal advantage.
The only bright spot of the night for the hosts was Ross County's defeat by Dundee, which leaves the Dingwall side bottom by two points.
Thistle travel to Dundee on Saturday where they might need victory to avoid automatic relegation given their goal difference is nine worse than the Staggies, who face St Johnstone in Perth.
Motherwell were without Richard Tait through illness and 18-year-old midfielder Turnbull was handed a first start, but the William Hill Scottish Cup finalists were otherwise at full strength and eager to atone for a 5-1 home defeat by St Johnstone.
Thistle started with intent and Conor Sammon flashed a header across the face of goal inside 60 seconds before Trevor Carson made a point-blank stop from Ryan Edwards' header.
But there were some nervy moments for the home fans as Motherwell forced a series of corners after Thistle's pressure subsided.
The hosts picked up again in the latter stages of the half and Carson made decent saves from Martin Woods and Chris Erskine.
Turnbull came close with a deflected strike after beating two men but the home fans were audibly lifted by news of a Dundee goal and Sammon shot just wide from 18 yards after a good run by Doolan.
However, Motherwell were enjoying more of the ball after Stephen Robinson's half-time switch, which saw midfielder Gael Bigirimana replace wing-back Stephen Hendrie.
And the visitors took the lead after Baily Cargill was adjudged to have fouled Chris Cadden. Turnbull whipped in the free-kick from the right and the unmarked Bowman headed home.
Carson parried a curling strike by Christie Elliott while Cedric Kipre was receiving treatment but the visitors recovered their composure once the French defender was back on his feet.
Thistle were struggling to create clear openings and Miles Storey could not capitalise when Kipre's slip handed them a chance, the substitute shooting beyond the far post.
Tomas Cerny kept Thistle in the game by saving Tom Aldred's header and they threw men forward in five minutes of stoppage time, but substitute Blair Spittal headed straight at Carson and Aldred made a crucial last-ditch tackle on Sammon.
Scottish Premiership Standings
POS | Team | GP | GD | PTS |
---|---|---|---|---|
1 | Celtic | 38 | +80 | 99 |
2 | Rangers | 38 | +56 | 92 |
3 | Aberdeen | 38 | -4 | 57 |
4 | Heart of Midlothian | 38 | +6 | 54 |
5 | Hibernian | 38 | -2 | 52 |
6 | St Mirren | 38 | -18 | 46 |
7 | Motherwell | 38 | +2 | 50 |
8 | Livingston | 38 | -24 | 46 |
9 | St Johnstone | 38 | -18 | 43 |
10 | Kilmarnock | 38 | -25 | 40 |
11 | Ross County | 38 | -23 | 34 |
12 | Dundee United | 38 | -30 | 31 |
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