Amir Khan admits he only has himself to blame after suffering a crushing fourth-round stoppage defeat to massive underdog Danny Garcia in Las Vegas.
Khan was floored three times as American Garcia exploited the Englishman's naive tactics to keep his WBC light-welterweight title and snatch his opponent's WBA belt.
Khan was taken to hospital for precautionary scans after the devastating loss, which was his second in succession after Lamont Peterson's tainted win over him last December.
"It wasn't my night," admitted the Bolton fighter.
"After watching the replays a little bit I thought I was coming in with my hands down and Danny took advantage.
"I respect Danny, he was countering very well against me."
Khan, now 26-3 with 18 early wins and two stoppage defeats, hinted he may have taken Garcia lightly.
His tactics backed that up as he tore at his opponent from the opening bell before becoming embroiled in a war which he lost spectacularly.
"We got a little complacent and he took advantage and he caught me," he said of Garcia's decisive left hook that sent him down for the first time.
"I was a little surprised the referee stopped it. I thought he was going to let us continue. My mind was clear and I thought my legs were okay but I respect the referee, the judges and the commission, maybe they made the right call."
Khan, who had perhaps naively talked about fighting Floyd Mayweather in the near future, had the WBA belt he lost to Peterson returned to him this week but lost it again to Garcia at the Mandalay Bay Events Center.