Bobby Zamora's first goal since his £1.5m move from Brighton, smartly taken in the first minute of extra time last night, saw Spurs through to a Carling Cup fourth-round tie at home to Manchester City.
But the gangling 6ft 4in forward, whose career began in the West Ham youth team, should not have been allowed to produce the flourish he had been yearning for with increasing anxiety in his eighth appearance for his new side.
Had West Ham in general - and Robert Lee or Jermain Defoe in particular - been able to finish off the chances they created, the hugely vocal visiting supporters would have been disappearing back to east London in celebratory mood.
While the game's highest high fliers may regard this tournament with a degree of disdain, there was no mistaking the intensity with which the First Division side approached this challenge against their north London rivals. Unfortunately, that intensity was translated into pre-match trouble, as police made about 80 arrests for disturbances near the ground.
But once the match got under way, West Ham's players produced a performance that was legitimately competitive without being aggressive. Their newly installed manager, Alan Pardew, a hyperactive presence on the touchline, expressed his satisfaction afterwards at the efforts his men had put in, but he, added, tellingly: "We've got to address the fact that we ain't scoring enough goals. It's a problem we've had from the start of the season."
Lee, the veteran midfielder, did well to get into scoring positions on three occasions during normal time, but on each occasion the end result failed to arrive. His first effort, in the 24th minute, was blocked by the defender Gary Doherty; his second produced a shot which bounced back off the post into the hands of the Spurs goalkeeper Kasey Keller; his third opportunity was lost as he failed to control the ball.
But the most glaring miss was produced by a striker whose transfer value is conservatively estimated at £10m. Played through by a meticulous pass from Michael Carrick after 65 minutes, Defoe shot too close to Keller, who was able to beat the ball away.
When the West Ham substitute Richard Garcia failed to control the ball in front of goal in virtually the last minute of time added on for injury, there was an ominous sense for the visitors that they had missed their big opportunity.
Barely had extra time begun than that intimation became reality as Zamora, accepting a pass from the substitute Jonathan Blondel, turned easily past his marker, Rio Ferdinand's kid brother, Anton, before firing home a low, left-footed cross shot.
Tottenham's caretaker manager, David Pleat, acknowledged that both Zamora and the home crowd had been getting a little edgy about his failure to score, but added: "If you keep withdrawing strikers, they lose confidence, so I was determined to keep him on even though there was a little bit of restlessness in the crowd, and he came good in the end."
Tottenham Hotspur (4-4-2): Keller; Carr, Doherty, Gardner, Ziege (Blondel, 60); Ricketts (Postiga, 76), Dalmat (Mabizela, 57), King, Konchesky; Keane, Zamora. Substitutes not used: Burch (gk), Bunjevcevic.
West Ham United (4-4-1-1): James; Stockdale (Ferdinand, 21), Dailly, Kilgallon, Quinn; Etherington, Carrick, Horlock (Mellor, 105), Lee (Garcia, 68); Hutchison; Defoe. Substitutes not used: Bywater (gk), Sofiane.
Referee: G Barber (Hertfordshire).