Crewe's 1-0 victory over Stockport County meant Wigan's lead at the top of the Second Division was cropped to nine points, with Cardiff having two games in hand of the leaders.
Jewell said: "I don't think any of our players performed anywhere near their capabilities.
"It was our worst performance of the season by some considerable distance.
"It was the manner of the defeat which disappointed me more than the defeat itself."
He remained tight-lipped about his post match discussions with his players but he refused to hide his disappointment at Latics' fourth defeat of the season.
Jewell said: "What I have said in the dressing room will remain in the dressing room.
"But that is not what I am looking for from our lads and they know that.
"Everything about us was poor. It was very un-Wigan like."
Latics now have 50 league and cup games on the clock and injuries have started to take their toll on the small 21-man squad.
But Jewell refused to accept tiredness as an excuse for the dismal display.
He said: "It has been the same for Plymouth and they had the long trip up here.
"We have worked exceptionally hard this season and I am not going to over-criticise the players.
"We are disappointed but we have only lost four out of 40 games.
"But if anyone had come here to watch their first game of the season, they would have thought how are we at the top.
"It reminded me of when I first came here 12 months ago. It was a bit disjointed and nobody won their personal battles.
"We have stressed all season that without fighting quality, graft and determination, you don't win football matches and we didn't deserve to win.
"It was a bad day at the office and that is what I have to try to put it down to."
The defeat was only the second time this season that the visiting team has grabbed all the spoils from the JJB – the last team to do so being Port Vale way in August.
And Jewell was quick to praise the persistence of Plymouth who have also taken the scalps of Oldham and Crewe on their travels.
The Wigan boss said: "The better side won on the day. They played well and we knew it wouldn't be an easy game as they are a good side.
"Their home form has probably been their achilles heel but they have done exceptionally well.
"They had players who worked harder than our players and that is what disappointed me."
Plymouth's assistant manager Kevin Summerfield, deputising for the absent Paul Sturrock who was on a scouting mission, showered praise on his team.
He said: "From 1 to 11, they got 10 out of 10. They were magnificent.
"That was comfortably our best performance of the season."
Article from the Wigan Evening Post.