It is narrated from Sayyidah Aisha (may Allah be pleased with her) that Sayyiduna Abu Bakr (may Allah be pleased with him) led the people in prayer, and the Messenger of Allah (peace and blessings of Allah be upon him) was in the row behind him.
Hadith Referenceصحيح ابن خزيمه / جماع أبواب قيام المأمومين خلف الإمام وما فيه من السنن / 1620