Whoever got (or was able to offer) one Rak‘a of the Fajr prayer (in time). [One Rak‘a means, one standing, one bowing, and two prostrations].

Narrated Abu Huraira:

Allah's Apostle ﷺ said, "Whoever could get one Rak'a (of the Fajr prayer) before sunrise, he has got the (morning) prayer and whoever could get one Rak'a of the'Asr prayer before sunset, he has got the ('Asr) prayer."

حَدَّثَنَا عَبْدُ اللَّهِ بْنُ مَسْلَمَةَ، عَنْ مَالِكٍ، عَنْ زَيْدِ بْنِ أَسْلَمَ، عَنْ عَطَاءِ بْنِ يَسَارٍ، وَعَنْ بُسْرِ بْنِ سَعِيدٍ، وَعَنِ الأَعْرَجِ، يُحَدِّثُونَهُ عَنْ أَبِي هُرَيْرَةَ، أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ " مَنْ أَدْرَكَ مِنَ الصُّبْحِ رَكْعَةً قَبْلَ أَنْ تَطْلُعَ الشَّمْسُ فَقَدْ أَدْرَكَ الصُّبْحَ، وَمَنْ أَدْرَكَ رَكْعَةً مِنَ الْعَصْرِ قَبْلَ أَنْ تَغْرُبَ الشَّمْسُ فَقَدْ أَدْرَكَ الْعَصْرَ ".