Mohammed Kudus gave the Hammers the lead, before Spurs fought back via goals from Dejan Kulusevski, Yves Bissouma and Heung-min Son, having also forced an own goal from Hammers keeper Alphonse Areola. Kudus would also see red in the second-half after clashing with Spurs pair Micky van de Ven and Pape Sarr.
Afterwards, Postecoglou said: "I thought we were good today. We had to work hard in the first half but we got back into the game after conceding. After that it was outstanding from the lads, good energy, some good goals although I thought we could have gotten a few more. Good day at the office."
On the half time change of Sarr for James Maddison, he continued: "Yes it was tactical, I just felt we needed a bit more running power in that midfield area. Pape gives us some good energy there and I thought that really helped us in the second half.
"Yes we felt the momentum, and that is what you want to create at home. The crowd played their part today. We have had periods like that so far this year and not capitalised but today we did capitalise. If we continue that we will be hard to stop.
"It is good getting goals across the team, guys like Brennan have been on the scoresheet recently but we do need more goals from midfield. Deki and Biss did a really good job in there and it was good for the skipper to come back in and score too."
Postecoglou added, "Great day for our fans. We know this fixture means a lot to them and the players have managed to send them home happy which is great."