Dundee United have moved to the top of the Scottish Premiership after a comfortable 4-1 victory over city rivals Dundee at Dens Park.
The Blues could have been back on level terms before the break when Philip Roberts found time to shoot from the right side of the area, but failed to guide his effort on target.
Instead, they fell further behind at the start of the second half when a set-piece delivery ended up at the feet of Ryan Dow and he steered the ball beyond Letheren's reach.
Dow nearly made the scoreline look more embarrassing for the Tangerines' local rivals, but his 66th-minute effort was kept out by Letheren.
However, the visitors from across the road did add a fourth when another set piece reached the head of Keith Watson, who scored from a tight angle.
Dundee's misery was complete when Konrad was given a red card after he lunged into a tackle and received a second yellow from referee Steven MacLean.
In stoppage time, Greg Stewart scored a consolation goal for the home side with the last kick of the game.
The result sees United move above Inverness Caledonian Thistle by virtue of scoring more goals so far this season.