Dundee United manager Peter Houston hailed Johnny Russell after the striker headed a late winner at Fir Park from the tightest of angles.
Russell met Keith Watson's deep, long cross near the byline but still managed to loop his header over Motherwell goalkeeper Darren Randolph and into the far top corner in the 84th minute to hand United a 1-0 win.
Houston, whose team prevailed in heavy rain, said: "On a difficult night I thought both teams tried to serve up a lot of football. One wee bit of quality has won us the game.
"It's not the first time Johnny Russell has scored a goal like that, he scored one at McDiarmid Park last season that was the exact same.
"I don't think it was a header across goal, he was trying to score. It deceived the goalkeeper and went over the top of his head but for me that shows great quality.
"It was a good ball in from Keith Watson, perfect delivery and a perfect header. Johnny Russell is capable of that, he is very good in the air."
Motherwell boss Stuart McCall could not criticise his players after they created several chances with Henrik Ojamaa hitting both the bar and the post.
McCall said: "We'll play a lot worse than that and lose.
"I found it very difficult to say anything negative other than the result.
"It was two good teams out there. How we have failed to score I don't know."