Nicholas Foreman abused the 14-year-old girl in Houndwell Park in Southampton on February 15 at around 10.30pm, Charles Gabb told jurors at Winchester Crown Court on Monday.
The prosecutor said that that the complainant had just met the defendant outside the Standing Order pub on the High Street earlier that evening.
Foreman, of Christchurch in Dorset, is currently standing trial on three charges of rape, one of sexual assault and four alternative charges of sexual activity with a child.
After they met outside the pub she was trying to get into, the pair went to Houndwell Park where the alleged offences took place at about 10.30pm, Mr Gabb said.
He told jurors: “At the relevant time he was 43, she was 14, the temptation that she presented to him he was just unable to resist and he embraced that temptation with gusto.
“In no more than 26 minutes, just 26 minutes it took from the very first time that these two have ever clapped eyes on each other to the time the deeds had been done.”
Mr Gabb said that the complainant made an excuse to get away from the defendant and members of the public called police when they saw her in a “distressed” state.
He added that Foreman then sent a message to his fiancee to say he was coming home while he attempted to order a taxi.
Mr Gabb said that the defendant denied the charges and told police in interview that he believed that she was aged over 18 and had consented to the sexual acts.
He said: “He denied raping her but he admitted having sexual intercourse with her saying it was fully consensual between the two of them.
“The defendant alleged she had told him that she was 18 and he then subsequently maintained to state that she had instigated everything therefore shifting the responsibility to this child away from him, effectively saying she started it.”
Mr Gabb added that the defendant had told police: “I do not believe in rape, I am a family man and it’s just not something I would participate in at any level.”
The four charges of sexual activity with a child act as an alternative where lack of consent is not proven but where the sexual activity with the under-age complainant is proven.
Foreman denies all eight charges and the trial continues.