The Eagles are due to appoint a new boss next week, with Wales chief Chris Coleman and former Real Madrid assistant Aitor Karanka thought to be the frontrunners to take over from Ian Holloway following his departure last month.
But in the meantime Millen was in charge as Palace ended a run of seven consecutive defeats.
Nevertheless, Millen said: "I'll certainly walk out with a smile on my face.
"We got what we deserved, in fact if we were being greedy we should have taken all three points with the chances we had, and if you are being critical we have to take them.
"But I'll never criticise players for missing chances. I asked them to be brave on and off the ball and they were.
"The belief is there, you can't ask for any more except to take your chances, that's the level we are at."
Dikgacoi was the first to fluff his lines when he made an almighty mess of a free header four yards out.
Then Chamakh headed wastefully wide from right in front of goal, and in the second half Thomas found himself one-on-one with Tim Howard.
The winger's chip beat the advancing keeper, but unfortunately for Palace it also cleared the frame of the goal and another chance went begging.
It means whoever takes over from Millen will inherit a team rock-bottom of the Barclays Premier League.
And Millen insists he is still in the dark about who will get the top job.
"I've not been involved in any discussions about names," he added.
"But we've got Hull next and I haven't planned that far ahead."
- Sports & Recreation
- Marouane Chamakh
- Jerome Thomas
- Ian Holloway
- Real Madrid
- Kagisho Dikgacoi