Sayyiduna Abu Qatadah (may Allah be pleased with him) narrates that the Noble Prophet (peace and blessings of Allah be upon him) said: Not offering the prayer due to sleep is not negligence; negligence is on the part of the one who does not offer the (first) prayer until the time for the next prayer arrives.
Hadith Referenceالمنتقى ابن الجارود / كتاب الصلاة / 153