Vincent Tabak could have walked away from the attack on Joanna Yeates but instead held her by the throat long enough to "squeeze the life out of her", a court has heard.
The 33-year-old could have released his grip on the 25-year-old's throat at any time during his "protracted and persistent attack", prosecutors claimed.
During his closing speech at Bristol Crown Court, Nigel Lickley QC said that instead of walking away Tabak held her by the throat until she fell limp in his hands.
He insisted that when the Dutch engineer went to Miss Yeates's neighbouring flat on the night of December 17 last year in Clifton, Bristol - a few minutes after she had arrived home - he had sex on his mind.
Once inside her home he used his 6ft 4in frame to overpower her and to kill her as the landscape architect desperately fought for her life.
"He knew what he was doing. He was in control and he knew she would die and he held her neck long enough, and coupled with a smothering second hand, to be sure that she would," Mr Lickley told the court.
"It goes to his intent and his intention to kill or cause really serious bodily harm.
"He knew she was struggling and fighting, he knew she was in pain, he knew she was frightened, he knew she couldn't breathe.
"Instead of letting go and releasing his grip and letting her live, he carried on and on and on until she went dead in his hands, her life extinguished."
The trial was adjourned until Wednesday when the judge, Mr Justice Field, will begin summing up. Tabak admits killing Miss Yeates but denies murder.