Two goals within the opening seven minutes got us off to the perfect start at the Gtech Community Stadium with Academy product Araya Dennis bagging our first before Ella Morris rattled in our second.
West Ham were awarded the first penalty of the tournament just before the break, which Estelle Cascarino duly converted to halve their deficit, however that lasted just a matter of seconds as we went straight up the other end and restored our two-goal lead through Signe Gaupset.
After the brief break, we then added a fourth with birthday girl Eveliina Summanen tapping in from close range to make sure of the win.
After defeating on opening day with Aston Villa running out 6-3 winners on Thursday, we bounced back at the first time of asking as we dispatched the Hammers to keep ourselves alive in the tournament.
Knowing a defeat would have left us unable to progress to the knockout stages, we made sure we started well.
Dominant throughout the clash, Dennis got us up and running with her first goal at the tournament. The young forward lashing in from just inside the area with just four minutes on the clock. We then didn't have to wait long for Morris to get involved as, from a pretty much identical position inside the area, the full back powered the ball home.
In an end-to-end game, West Ham did have their opportunities and should have probably been level by the break had Vivianne Asseyi been able to keep her effort on target when one-on-one with Eleanor Heeps before the goalkeeper then pulled off an incredible save to deny Tuva Hansen from point-blank range.
They did get on the scoresheet with a minute left of the first period with the maiden penalty of the tournament. Ruby Mace was adjudged to have committed a foul in the box and, after the referee pointed to the spot, Cascarino rifled home.
However, we didn't let that goal dampen our spirits as we went straight up the other end to restore our two-goal advantage through Gaupset. The Norwegian is enjoying quite the tournament so far with three assists and now a goal to her name.
After a frenetic first half, it was a much more quiet game in the second with both goalkeepers rarely troubled.
Eleanor Heeps did have one impressive save to make, denying Asseyi on the volley with a superb use of reflexes on the line but had little to do after that.
But it was a similar story down the other end where, bar Summanen's tap in on 25 minutes after Cathinka Tandberg had rounded Megan Walsh, the Hammers stopper was also largely untroubled.
The win moves us up to second in our group behind Manchester United, ahead of Aston Villa on goal difference.
We face United in our final game and it is likely we will need to win that game if we are to go through to the knockout stages.
Spurs: Heeps, Morris, Bartrip (c), Nilden, Gaupset, Holdt, Tandberg. Substitutes: Jackson, Mace, Hills, Summanen, Oukriss, Pierre, Dennis.
West Ham: Walsh, Siren, Hansen, Ueki, Bose, Asseyi (c), Cascarino. Substitutes: Szemik, Endo, Belloumou, Zadorsky, Ziu, Brasero, Piubel.