Sulayman bin Yasar (may Allah have mercy on him) narrates from Sayyiduna Zayd bin Thabit (may Allah be pleased with him) concerning a man who was alone in seclusion with a woman; he says: I did not have intercourse with her, and the woman says: He did have intercourse with me. He said: The woman's word is to be accepted.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصداق / 14485