The Belgium striker completed his switch to Selhurst Park from Liverpool earlier on Saturday, too late to play at Spurs, and Pardew expressed his regret as Palace became the only team in the league so far to lose their first two matches.
New Tottenham signing Victor Wanyama headed the winner from a corner in the dying minutes to seal the points for the home side but Pardew was unhappy with his team's failure to score when they were dominating earlier in the second half.
"It's galling for us because the players have given everything today," he told reporters.
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"We had a bit more verve in our play, a bit more industry. Certainly, after halftime we had a great spell. When you come to places like Tottenham you have got to score in that spell, and that's the issue that this team have.
"The signing of Christian is to try and address that," he added after splashing out for Benteke in a deal British media said could be worth up to 30 million pounds.
Pardew, whose team lost their league opener against West Bromwich Albion 1-0, said Benteke could have made the difference against Tottenham if he had been eligible to play.
"There's one thing that's always impressed me about him," said the Palace boss. "He gets the sort of goals you would expect, but now and then he just pulls a rabbit out of the hat with a goal.
"I think that's just something we need, like today, just one moment that could change the whole course of this game. In that 20 minute period maybe he could have done something for us."
(Reporting by Simon Jennings in Bengaluru; editing by Ken Ferris)
