Ross County blew the chance to narrow the gap on leaders Dundee as they failed to make their possession count.Partick Thistle always looked dangerous on the break, mainly through Liam Buchanan who slotted the ball home to open the scoring after half an hour.
Early in the second half, Thistle's Brian Hodge beat Michael McGovern with a stinging shot from 20 yards.
Sub Andrew Barrowman pulled one back for County with 15 minutes remaining but Thistle held on for the points.
The lively Buchanan beat the County offside trap for Thistle's opener. The ball was played over the top of the visitors' defence, the flag stayed down, and the striker fired past Michael McGovern.
County, though, had plenty of other chances, with the Jags' Jonny Tuffey saving well from Garry Wood and Scott Morrison.
Partick: Tuffey, Corrigan, Conroy, Shields, Robertson, Archibald, McNamara, Rowson, Buchanan, Lovell (Donnelly 71), Bryan Hodge (McKeown 66). Subs Not Used: Halliwell, Grehan, Erskine.
Goals: Buchanan 30, Bryan Hodge 54.
Ross County: McGovern, Girvan, Morrison, Kettlewell (Craig 46), Boyd, Watt, Gardyne, Lawson, Wood (Barrowman 64), Brittain (Scott 72), Vigurs. Subs Not Used: Malin, Di Giacomo.
Goals: Barrowman 76.
Attendance: 2,192
Referee: C Brown
Source: BBC Sport
Source: BBC Sport