Dundee slipped to a first defeat in eight games as Raith Rovers came from behind for victory at Stark’s Park.
Osman Sow gave the Dark Blues the opener in just the fifth minute.
But former Dundee defender Kyle Benedictus equalised midway through the first-half before Reghan Tumilty’s stunner put Rovers in front early in the second-half.
Another superb strike from Kai Kennedy put the game beyond the Dens Park men in the 60th minute.
Dundee new boys
Dees boss James McPake kept new signing Jason Cummings in reserve until early in the second-half.
But he handed an instant debut to on-loan Spurs youngster Malachi Fagan-Walcott in a defence shorn of the injured Liam Fontaine, Jordon Forster and Jordan McGhee, plus the ill Lee Ashcroft.
There was also a bow for 19-year-old Sam Fisher at the heart of the Dens Park rear-guard and for Fulham kid Timmy Abraham, brother of England star Tammy, in the Raith ranks.
But it was on-loan Dundee United winger Paul McMullan who made an immediate impact on his Dundee debut.
The 24-year-old provided the assist as the Dark Blues took a fifth-minute lead
Charlie Adam made the most of possession 40 yards out by feeding McMullan on the right side of the box.
The wide man’s pinpoint cross was whipped in perfectly for Sow and the striker clinically volleyed in from six yards out.
But the visitors were made to pay for a moment of slackness as Raith levelled things up again in the 22nd minute.
Raith get into the game
Dan Armstrong played a corner from the right short to Kennedy and the on-loan Rangers winger’s chipped cross was headed in from close range by Benedictus.
Jack Hamilton had to look smart to deny Rovers a second as he beat away Abraham’s effort and a fierce Kennedy effort as the home side finished the half on top.
But there was nothing he could do as Rovers took the lead eight minutes after the break.
This time, Raith’s short corner routine failed to pay off but Dundee’s clearance was picked up by Tumilty and his sensational drive flashed into the bottom corner from 30 yards out.
Six minutes later, Raith – who later introduced on-loan Dundee United winger Adam King for his debut – increased their lead with another stunner.
Brad Spencer found Kennedy in space on the left and he danced inside Christie Elliott and curled a magnificent shot into the far corner of the net.
Sow headed an Adam free-kick wide before hitting the outside of the upright with a curler 15 minutes from time as Dundee’s hopes of a comeback slipped away.