Impressive finishes from Jamie Murphy, Chris Humphrey and Francis Jeffers secured a 3-0 victory for the home side in a one-sided quarter-final replay at Fir Park.

Motherwell took control from the first whistle and never looked back after Murphy netted an eight-minute opener.

McCall's side will now face St Johnstone at Hampden on April 16 after vindicating their manager's faith in his players.

Well have been inconsistent since McCall took charge, not helped by injuries to their small, squad, most notably when they followed victory over Celtic with a 3-0 defeat by Inverness.

So McCall was delighted to see them rise to the occasion.

"I'm like a broken record, but I've said it after being in the job for a couple of weeks, when we are at it we are a match for anyone," he said.

"Thankfully tonight we were at it.

"We have matched Celtic and we matched Rangers in the (Co-operative Insurance Cup) semi.

"I have probably got more belief in the lads than they have themselves.

"It was an all-round team performance, the three goals were outstanding. They deserve all the plaudits.

"It was great to have the supporters behind us, there was 8,500 fans here, and I'm delighted for them. We put everything into it and we were on top of our game.

"Our lads had a little sniff of it a couple of months ago against Rangers and I think they showed how much it meant to them to get back."

Dundee United manager Peter Houston felt his team produced their worst performance of his reign as their defence of the trophy ended in abject fashion.

"The hungrier, more determined team won," Houston said.

"We gave Motherwell a head start in the first game and we talked about that first goal, and they score after seven minutes. But I would be making excuses if I didn't say the hungrier, better team won.

"I think that's the poorest performance since I took over as manager, and I include the 7-1 defeat by Rangers in that.

"We played well at times at Ibrox but tonight our second shot at goal came in the 89th minute.

"That's not the United team I have known, even in the last month.

"We came off five victories in the league but we just didn't turn up."