Natalia Woolley, 38, who described herself on escort websites as "alluring to all men and incredibly sexy", is accused of leaving 69-year-old Winston Fernandez slumped lifeless against his bed.
It is alleged she soon started trying to cover her tracks. She called her mobile phone provider to ask if her iPhone could be traced, then stopped using her phone, jurors were told.
Guildford Crown Court heard that Mr Fernandez, who lived alone in a four-bedroom house in Epsom, Surrey, was not found until almost a month after his death when a concerned neighbour contacted police.
William Saunders, prosecuting, said Woolley was registered with the Diamond Escorts and 24-Carat Escorts agencies, and used the names Lenka and Alice to ply her trade.
Opening the case, he said she featured in "various poses" on the agency websites and in one described herself as 26 but "mature".
"It says that this girl is alluring to all men, and incredibly sexy with a curvaceous body," he told the jury of six men and six women.
Mr Fernandez saw Woolley a number of times in the months leading up to his death, and wrote a review on her website page saying he was "addicted" to her.
On Boxing Day last year, he wrote about a visit on November 25. "What a girl she is," he wrote. "I have never been disappointed... It is a pleasure to be with you. I will spend a lifetime with you."
The court heard that Mr Fernandez, whose wife had died in 2000, was estranged from his two sons and was a "lonely, difficult" man who "frequently found comfort in alcohol" and had started to use the services of escort agency girls.
On the evening of January 16 this year, Woolley had gone to his address at his request, Mr Saunders said.
"Miss Woolley was the last person to see him alive. By the time she left in the early hours of January 17, he had suffered multiple injuries and was left dead, or left for dead. He was not found until February 13."
The barrister said Woolley had cut both his telephone lines before making off into the night.
Miss Woolley, of West Kensington, London, who wore orange-rimmed glasses, a cream overcoat and a pink hair-grip to tie back her blonde highlighted hair, listened to the proceedings through headphones via a Russian interpreter. She denies murder
She is alleged to have inflicted a "sustained and brutal assault" on her frail victim, causing terrible injuries all over his body.
Mr Saunders told the jury the defendant kicked, punched and stamped on Mr Fernandez, fracturing 17 ribs and breaking his larynx in two places.
He said: "He was found fully clothed, but in a state of partial decay, and the post-mortem of him revealed that he had been beaten to death. By beaten, I mean punched and kicked."
The Home Office pathologist had found a "large number of injuries, some severe, and some requiring severe force" across the pensioner's head, face, neck, torso, legs, back, arms and hands.
Mr Saunders said in interview the defendant said Mr Fernandez had locked her into his house, demanded she perform sex acts, and attacked her by pinning her down and grabbing her legs.
She said he had drunkenly fallen on the floor as they argued, the court heard.
"The reality," he said, "is that she had repeatedly punched him, kicked him and stamped on him using severe force. Her account was so far removed from the truth - that she had killed him.
"She must have left him dead, or very nearly so. Before she left she cut the telephone lines. She was to say in her interview that she did it to stop Mr Fernandez calling her. Really, the truth is that she was venting her rage, as she was clearly enraged that night."
The prosecutor said Woolley soon started trying to cover her tracks after she left the dead Mr Fernandez dead or dying. She called her mobile phone provider 3 to ask if it was possible her iPhone could be traced.
"She realised that if her phone could be traced to a location, then so could she," Mr Saunders said. Woolley then stopped using her phone.
The trial continues.