It is narrated about Sayyiduna Salman bin Sakhr al-Ansari (may Allah be pleased with him) that he made zihar against his wife, then had intercourse with her before offering the expiation, so the Prophet (peace and blessings be upon him) ordered him to offer only one expiation.
Hadith Referenceالمعجم الكبير للطبراني / باب السين / 6303