Andre Villas-Boas has described West Ham's second goal at White Hart Lane as "the key to the game" on Tottenham's official website.
The north London outfit were surprisingly beaten 3-0 by their local rivals, with former Manchester United player Ravel Morrison capping the victory with an incredible solo goal.
The defeat was the first time this season that Spurs have lost at the Lane, and Villas-Boas is under no illusion as to what was the key moment of the match - Ricardo Vaz Te's 72nd minute goal.
"That was probably the key to the game," said Villas-Boas. "We looked to go to two strikers to have a go, but that's when 2-0 happened and made it very difficult for us to come back into the game."
The win takes Sam Allardyce's side clear of the relegation zone and up to 13th in the table.
Almost equally as pleasing for Hammers fans will be the form of youngster Morrison. His 79th minute wonder-goal was his fourth of the season, showing why he was called up to the England under-21 squad.
Each of West Ham's goals came within the second half, while the Tottenham manager believes before the flurry of goals the game could have swung either way.
"In the first half, both teams played well, wanting to win and it was an intense half," he added.
"There was a great rhythm to the game and either team could have taken the lead. It was completely open.
"In the second half we came out strongly with the right frame of mind and deserved to take the lead."
The defeat leaves Tottenham in sixth with a tricky away fixture against Aston Villa after the international break.
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