Dundee United boss Jackie McNamara hailed Nadir Ciftci after his double sent the visitors on their way to a 5-0 William Hill Scottish Cup win at Inverness Caley Thistle.

The former Portsmouth player put United 2-0 up inside 27 minutes of the quarter-final clash as he capitalised on two balls over the top, which home goalkeeper Dean Brill and defender Josh Meekings failed to deal with both times.

Ciftci was sent off in United's League Cup quarter-final defeat at Inverness in October and McNamara praised his determination to get United on top.

"I thought we were excellent from the start," said McNamara, whose side will meet Rangers or Albion Rovers in the last four. Nadir took his first goal really well and showed the desire to get on the end of the second one.

"When he's on form he is unplayable. The big thing for the first one is the strength he has got, and the second one you can see the lad looking over his shoulder looking for him. He has real pace and power and I thought he was fantastic.

"We were very comfortable in the match, to a man we were excellent."

United have now won five matches in succession and McNamara sees no reason why they cannot go all the way in the competition.

"We got to the semi-final last year against Celtic and we ran them close," the former Scotland international said. "So it would be good to get to the final this year and there is no reason why we can't go on and win it.

"That's five games we have won on the bounce. That breeds confidence in the players and we are scoring goals as well."

Gavin Gunning added a third from the penalty spot after he was fouled by Graeme Shinnie and goals from Gary Mackay-Steven and Stuart Armstong completed the rout before the hour mark.

And Caley Thistle's misery was compounded by straight red cards for Greg Tansey and Marley Watkins, both of whom fell foul of referee Willie Collum for studs-up challenges on Paul Paton.

Inverness boss John Hughes admitted they had no bearing on the outcome but he struggled to accept they were worthy red cards.

"A sending-off for me is going over the top of the ball, when you go to damage," Hughes said. "Tansey has put his studs round the back of the ball, the guy has kicked it and cleared the ball and gone down like a ton of bricks. He is up again running about as soon as Tansey is sent off.

"Then Marley slide-tackles, puts his studs behind the ball, a great tackle in my day. I don't know what justifies red cards these days."

Hughes added: "Take nothing away from Dundee United, but we beat ourselves. The first two goals were very avoidable and the second one was comical.

"It was a penalty and we were beaten. I think the sendings-off were irrelevant. I don't know what justifies a sending-off at this moment in time, but we were 3-0 down before the first guy gets sent off."