Despite a dominant first-half display, a Kris Doolan strike sealed the three points for the home side at Firhill.
By Joe James
United made only one change to the side that on Saturday turned over St Johnstone at McDiarmid, suspension forcing Coll Donaldson to make way from the match-day squad with Paul Dixon returning at left back.
It was a completely dominant first half, United recording a total of 14 shots and really looking to pile the numbers forward in every attack. Ryan Dow in particular was handed three huge opportunities to open the scoring after clever cut-backs, however, the United attacker's attempts were struck well above the bar.
With just under twenty minutes remaining, a clinical strike from Kris Doolan inside the box saw Thistle take the lead, the goal that proved vital and gave the points to the home side.
Thistle 1 - 0 United
Thistle: Cerny, Miller, Seabourne, Welsh, Booth, Osman, Amoo, Doolan (80' Edwards), Lawless, Frans (48' Dumbaya), Fraser (13' Pogba).
Unused subs: Scully, Elliott, Nesbitt, Nisbet.
United: Kawashima, Dixon (78' Ofere), Gunning, Morris, Knoyle, Rankin, Paton, Demel (67' Spittal), Anier, Dow (78' Fraser), Mckay.
Unused subs: Szromnik, Dillon, Murray, Durnan.
Referee: Andrew Dallas