THERE was much to be sad about at Tannadice yesterday and yet so much to cherish.

Dundee United's squad warmed up ahead of this resounding victory wearing T-shirts that were a gesture of solidarity with their 20-year-old club-mate Jordan Moore, who has been receiving treatment for skin cancer.

Then they gathered in the centre circle with their opponents, black armbands on their tangerine shirts, as the stadium broke into 60 seconds of applause in memory of Frank Kopel, a United stalwart struck down by the curse of Alzheimer's before his untimely death at the age of 65 earlier this month.

There would be much more in the way of acclaim from the crowd before the afternoon was out, though. Indeed, there could have been no finer tribute to Kopel than this display of quick, inventive football.

United can be unpredictable and inconsistent, but you forgive them everything when they play like this, with freedom, with ambition and with a clinical attitude in front of goal.

The outstanding Nadir Ciftci scored twice in the first half with the equally impressive Stuart Armstrong, Ryan Dow and substitute Brian Graham netting in the second, before Lionel Ainsworth got a late consolation for the visitors, who are now fighting to hold on to third place in the SPFL Premiership rather than rival Aberdeen for second.

"We are still chasing the teams in front of us and this gives us a chance," said United's assistant manager Simon Donnelly, the United assistant manager, who marshalled things from the dug-out with Jackie McNamara suspended. "It was up there with our best displays.

"Armstrong was very good. When he is in full flight like that, no-one can keep up with him. It was also a great gesture to show support to a lad [Moore] in difficult times. He is a great kid and it was a great show for him."

The goal that set United on their way was a thing of some beauty. Ciftci laid the ball off to Armstrong, who was watched by Queen's Park Rangers, with a deft flick and moved into space to receive the return after his midfield team-mate had skipped past Stephen McManus.

There was still some work to do at the edge of the area, but Ciftci showed quick feet to leave Shaun Hutchinson bamboozled before sending a lovely curling effort into the top corner with his right boot. Paul Paton had a chance to make it 2-0 after 15 minutes after Ciftci's delightful chip took out the Motherwell rearguard, but his attempt to lob Gunnar Nielsen, lacked conviction and McManus recovered to head the ball out at the far post.

However, United deservedly doubled their lead after 40 minutes. Gary Mackay-Steven, another terrific performer, produced some trademark trickery on the right before releasing a crossfield pass that found Armstrong in acres of space.

The Scotland under-21 captain spotted Ciftci powering through the middle with the Motherwell defence trailing in his slipstream and picked him out with a delightfully-measured cross.

The only thing that could have saved the visitors was linesman Stuart McMillan raising his flag for offside, but he kept it by his side and Ciftci beat Nielsen from around 12 yards.

Motherwell, who introduced Ainsworth and Craig Moore at half-time, squandered a great chance just after the break. Keith Lasley, who handed the captain's armband to Stevie Hammell to mark his 500th appearance for the club, blazed a close-range shot over the bar after a long throw-in from Craig Reid somehow made its way to him at the far side of the box.

Just after the hour, Armstrong killed the match stone dead as a contest, outpacing Hutchinson to move on to a forward pass from Ryan Dow and send the ball whizzing high into the right-hand corner off Nielsen's glove. Dow got in on the scoring act when he chested down a cross from Andy Robertson and shot home.

Robertson also provided Graham, on for Ciftci, with a clear opening towards the end and the forward made the most of it by sliding the ball under Nielsen.Ainsworth pulled one back in the closing stages with a long-range shot that took the slightest of deflections off Robertson, but his side's goose had been cooked long before then. "They were very, very good and we were very, very poor," said Motherwell manager Stuart McCall. "We have to win our last three games to get to where we want to be and we can do it."