Richard Whyte, 24, of Camberwell, south London, showed no emotion as he was convicted by the jury at the Old Bailey after 90 minutes' deliberations.
The court was told that 29-year-old Caroline Williams, a stage manageress, struggled to defend herself against Whyte but was battered round the head and had a screwdriver-type weapon driven into her neck.
Whyte was trapped by DNA tests and a bloody footprint which matched him to the murder scene. He had been arrested on another matter, but police recognised him from a poster to find Mrs Williams's killer.
Her husband, Tim Williams, who also works in theatrical production, had been in Plymouth preparing a production of the opera Carmen, at the time of the murder 18 months ago.
Yesterday he sat in court staring at Whyte as he was jailed. Mr Williams had been planning to start a family with his wife, three years his junior.
He said afterwards: "He has been convicted, but it cannot bring her back. She was the brightest, most joyful person - so full of potential. It is a tragedy that potential was brought to such a rapid close."
Mr Williams had returned from Plymouth for a weekend reunion with his wife, when he found her body in a pool of blood on the bed in their bedroom.
"It did not take long before I realised she was dead," he told the court. "I felt her head with both of my hands. My memory of this is hazy. There was some clothing by her head which I moved to reveal a pool of blood."
Her killer got into the house initially bent on burglary. "He attacked her, raped her and then murdered her," said Mr Nigel Sweeney, for the prosecution.
"She was murdered by a combination of a number of blows about the head. He then left taking her purse, cash, cheque book and cards."
Whyte's trial had been halted twice last year - prolonging the ordeal faced by Mr Williams. It was first stopped for technical reasons and on the second Whyte became mentally ill and was transferred to hospital for assessments and treatment.
Fit again to stand trial this month, he denied murdering Mrs Williams on 20 August 1994.
Mr Williams said he and his wife had just celebrated their second wedding anniversary with a trip to Kenya when they decided it was time to start a family. "She would have made a wonderful mother," he said outside court.
Mrs Williams's mother, Mrs Wendy Turner, said that because they had waited for so long "the mourning process has been put on one side. She was such tremendous company - we miss her so much, both her family and her friends."Reuse content