The court heard that McHendry told police: "When I turned round I noticed he (Dida) was on the ground.
"I just ran straight back out over the other side."
Asked by officers why he had invaded the pitch, the court was told McHendry replied: "I don't know, just obviously the goal getting scored.
"It's the top team in Europe and we just beat them at Parkhead.
"I just got carried away."
The Crown said the police asked McHendry how much he had had to drink before the game, to which he replied: "I had a couple."
The 27-year-old went to Celtic Football Club the day after the game and told staff he was the person responsible for the invasion.
The club promptly slapped a lifetime ban on the fan, who was not a season ticket holder.
The court was told that McHendry then went to a nearby police station where he was charged with causing a breach of the peace.
In another interview transcript read out to court, McHendry told police he realised the possible implications of what he had done.
He said: "I realised how serious it was. When I saw it yesterday morning, I realised I had to do something."
He said he hoped Celtic would not be punished heavily.
The court also heard that McHendry's momentum had propelled him on to the pitch.
"I came down the stairs and just carried on. I don't know what I was doing."
In mitigation, Raymond McIlwham said his client was extremely contrite. He also pointed out that McHendry was now subject to a lifetime ban from Celtic Park.
Sheriff Craig Scott told him he viewed the incident seriously.
He said: "Whatever your motivation may have been on Wednesday, your action may well have given rise to incalculable harm as far as Celtic Football Club is concerned.
"The court must take a serious view."
He called for reports to be prepared on and McHendry will next appear at Glasgow Sheriff Court on November 2.
