Summerville notched his first Hammers strike since moving from Leeds United in the summer.
The Hammers were under the cosh in the first half at home, but emerged stronger in the second half and won 2-1 thanks to a controversial penalty scored by Jarrod Bowen.
“I told Mo (Kudus) that when I came on I was going to score, and that I was going to celebrate with him!” said Summerville about his goal to club media.
“I like Mo a lot - I look up to him on and off the pitch, and the emotions all just came out.
“I’m very happy with the goal. You always have to be alert in the box, I was was switched on and I was happy to see the ball fall to my feet.
“I’ve had to be patient at times so far this season, but when I come on I just try to give energy to the team. I think that’s why West Ham wanted me in the summer, and I think I managed to bring some joy to the stadium today.”