Yahya related to me from Malik from Rabia ibn Abi Abd ar-Rahmanthat if Abdullah ibn Umar arrived at the mosque and the people hadalready prayed, he would begin with the obligatory prayer and not prayanything before it. (IT)
USC-MSA web (English) reference: Book 9, Hadith 78 (IT)
Arabic reference (IT): Book 9, Hadith 409 (IT)