John Sheridan apologised to Plymouth supporters for his side's capitulation in the 3-0 loss to Wycombe.
Sam Wood opened the scoring with a thumping long-range strike on 70 minutes before top scorer Dean Morgan doubled their tally four minutes later.
On-loan Sunderland forward Billy Knott sealed Wycombe's win, clipping the ball over home goalkeeper Luke McCormick during the five minutes of stoppage time.
Sheridan said: "I just think that when the first goal went in we went under and that's what has disappointed me more than anything else.
"In the second half when we came out I thought we were probably the better team for 15 or 20 minutes but then once the goal went in we just went to pieces.
"It was a frustrating afternoon, they came to frustrate us and full credit to them they did what they have had to do.
"I thought the goal could have been avoided, because we were on top at that time, and I must admit I am struggling to explain it because I couldn't see it coming.
"Rommy (Boco) cut inside and had a good chance just before they scored and I don't know if it was chested down or a handball. I couldn't tell but there weren't that many chances. They have had three shots and scored three goals. I don't think Luke really had to save anything.
"I apologise to the supporters. We just went to pieces after the first goal went in and I definitely expect a lot more fight. Even when the second goal went in there were still 15 more minutes to go.
"Sometimes I have to say to myself 'Take it on the chin, you weren't good enough' and I have just got to accept it sometimes and say the better team won."