For the second game in succession, Dundee gave themselves a mountain to climb.
However, unlike Friday night’s match against Hearts at Dens, there was to be no dramatic fightback at Firhill.
First-half strikes from Callum Booth and Kris Doolan had Partick Thistle well on top and comfortably in control of the game.
Dundee rarely threatened throughout and could have no complaints about the result.
Dark Blues boss Paul Hartley made two changes from the side that started against Hearts on Friday night with Julen Etxabeguren replacing Kevin Gomis with one of the scorers against the Jambos, Paul McGowan, returning at the expense of Mark O’Hara, who dropped out of the squad altogether.
Jags boss Alan Archibald, the longest-serving manager in the Premiership, made one change from the team that beat Ross County the same evening with Adam Barton coming in for Steven Lawless.
Neither side could carve out a clear-cut opportunity in the opening stages with both keepers virtual spectators.
However, that all changed in the 16th minute as the Jags took the lead.
Kosta Gadzhalov looked to have won the ball cleanly from Doolan 20 yards from his goal but referee Alan Muir decided he had committed a foul.
Home full-back Booth stepped up to take the free-kick and bent it past the wall and into the net beyond the despairing dive of Dark Blues keeper Scott Bain.
The Dundee players were still disputing the award of the free-kick as the teams lined up to restart the game but despite their sense of injustice, the simple fact remained that they were a goal behind.
Hartley’s men then had a chance of their own when Thistle conceded a needless free-kick 20 yards from their goal but this time, Tom Hateley hit his free-kick well over.
The Jags had an opportunity in the 35th minute when former Dundee United midfielder Chris Erskine played in Christie Elliott down the right but his shot from a tight angle flew straight into Bain’s arms at his near post.
Dundee had plenty of possession but were struggling where it mattered in the final third with home keeper Tomas Cerny finally called into action in the 40th minute when he made a comfortable save from a long-range Cammy Kerr shot.
Thistle then broke dangerously from inside their own half with Ryan Edwards playing in Erskine but Bain made a vital block as he pulled the trigger.
However, the keeper was helpless to prevent the Jags extending their lead in the 44th minute. Dundee were carved open once more with Bain again denying Erskine but Doolan followed up to fire home the rebound to make it 2-0 at the interval.
Thistle tails were still up at the start of the second 45 with the dangerous Erskine trying his luck from long-range with the ball flying onto the roof of Bain’s net.
The Dark Blues then had a great chance of their own when Kevin Holt had a clear sight at goal but he shot straight at Cerny who easily saved.
There was a flashpoint in the 65th minute when Elliott was late on Holt with Mr Muir booking the Thistle player once the dust had settled.
Dundee looked increasingly desperate as the Jags really started to enjoy themselves.
However, the home side had a big scare in the 77th minute after Booth chopped down Cammy Kerr with Hateley sending in a superb free-kick from the right with Marcus Haber rising highest to bullet a header but it was straight at Cerny who saved easily.
Sub Rory Loy then tried his luck with another header but again it was too close to the home keeper.
Dundee continued to huff and puff but Thistle easily dealt with all they threw at them and Hartley’s men will have to dust themselves down quickly before the visit of St Johnstone to Dens on Saturday in the Tayside derby.
Attendance – 3,758.
Partick Thistle – Cerny, Booth, Welsh, Lindsay (Gordon, 45), Osman, Doolan, Erskine (Azeez, 66), Barton, Elliott, Devine, Edwards.
Subs not used – Stuckmann, Amoo, Lawless, Wilson, McDaid.
Dundee – Bain, Holt, Vincent (El Bakhtaoui, 58), O’Dea, Hateley, Etxabeguren(Loy, 78), McGowan, Haber, Gadzhalov, Kerr, Wighton.
Subs not used – Mitchell, Williams, Ross, Curran, Gomis.
Referee – Alan Muir.