Albion's four game unbeaten run came to an end at Anfield after the Baggies were blown away by Liverpool in the first half.
The Baggies were punished for two lapses in concentration at the back as Liverpool raced into a two goal lead inside 35 minutes.
Gareth McAuley fired home from close range nine minutes from time but it was too little, too late for Albion.
"In the first half we were OK, just two poor mistakes. It is quality at times when we get the ball, to get in their final third," said Pulis.
"In the second half we had a go, it opened up at our end and Ben made some wonderful saves. We made changes, freshened it up and caused them problems.
"You know if you get a goal it puts them on the back foot and it is a shame it didn't come earlier.
"We lack certain qualities we are looking for. The squad has improved, they have faults and we accept that but they worked hard today."
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