Palace routed the Hammers 5-2 at the same venue in April as part of six victories in a seven-match unbeaten run to finish the 2023-2024 season and also beat them in a pre-season tour match in the United States.

However, goals from Tomas Soucek and Jarrod Bowen consigned Palace to defeat on this occasion, leaving Glasner's men without a point from their first two games of 2024-2025.

A frustrated Glasner said Palace had to forget the strong end it had to last season.

"We can't dream of what we were doing three months ago," Glasner said.

"It's now up to us to keep calm and not be too disappointed. We will sleep really badly tonight but tomorrow the sun will rise."

Palace sold defender Joachim Andersen to Fulham this week and also saw Michael Olise, a goalscorer against the Hammers in April, depart for Bayern Munich earlier in the transfer window. Long-time servant and cult hero Jordan Ayew also left for Leicester City.

Glasner acknowledged his squad could do with a couple of extra bodies in light of those departures.

"We have lost seven and brought in three," he said.

"Maybe we need one or two. But this is what we're talking about, to have a good balance in the team. Let's see what happens next week."

Speaking to the club’s in-house media, Glasner said there were still plenty of positives to take.

"I think we played OK. It's maybe not the top level, but it's OK, we created chances, we created situations," he said.

"We have to stay positive, we have to stay together, especially when the time is not so sunny."

Victorious manager Julen Lopetegui, meanwhile, was in a positive mood after his side claimed its first three points under his leadership.

"It feels good to win and we're happy to achieve these three points," he said.

While the Hammers had much of the play for the second half, Palace was not without its moments throughout the 90 minutes.

Ebere Eze stood out, with his best effort rattling the crossbar shortly before half-time, while Odsonne Edouard was also a danger.

"This stadium is always difficult to win in, against a very good team. They have good players, a good coach and good ideas," Lopetegui said.

"We have to defend well to give us the platform to win. We had to be together to overcome the bad moments.

"We did and were resilient. We worked so hard for the result."