Andre Villas-Boas suffered the biggest home defeat of his reign as Tottenham manager on Sunday evening as West Ham ran riot, claiming a fine 3-0 victory in north London thanks to three goals in 13 second-half minutes.
Ricardo Vaz Te doubled West Ham's lead after Winston Reid's opener and Morrison then brought the away fans to their feet with a fantastic solo goal.
The former Manchester United man picked the ball up inside his own half and slalomed past Jan Vertonghen and Michael Dawson before cleverly lifting the ball over Hugo Lloris.
West Ham had struggled without the injured Andy Carroll so far this season, but Morrison performed admirably up front, much to Allardyce's delight.
"That was a genius goal," the West Ham boss said.
"Tottenham had conceded two goals before today, but he just headed directly to Vertonghen and Dawson, slipped them like they weren't there and he used his outstanding ability to dink the goalkeeper.
"For me you will struggle to see a better goal this season."
Many questioned Allardyce's decision to sign Morrison from United last year."
The midfielder was convicted of two counts of witness intimidation and he was also fined ?7,000 by the Football Association for a homophobic tweet.