The khutbah does not take the place of the two rak’at of Jumu’ah. This is not established from the Prophet (ﷺ). It is only a weak narration narrated from Umar ibn al-Khattab (may Allah be pleased with him).
Shaikh al-Albani rahimahullah wrote:
“As for what is reported
from Ibn Abi Shaybah (1/126/1) from Yahya ibn Abi Katheer who said: It was narrated from Umar ibn al-Kattab that he said: Verily the Khutbah was established in place of the two rak’aat. If he does not catch the khutbah, then let him pray dhuhr”.
It is not authentic because of the disconnect between Yahya ibn Abi Katheer and Umar
[Ajwibah an-Naafi’ah ‘an asilatul lajnah masjid ul-Jaami’ah pg. 49]
If someone catches one rak’ah of the Jumu’ah prayer, then he has caught the Jumu’ah.
The proof is:
مَنْ أَدْرَكَ رَكْعَةً مِنْ صَلاَةِ الْجُمُعَةِ أَوْ غَيْرِهَا فَقَدْ أَدْرَكَ الصَّلاَةَ
Whoever catches one Rak’ah of Friday prayer or other than it, then he has caught the prayer
[Saheeh Ibn Majah no. 1123]
As for coming late to Jummah, then a person will not be recorded in the scrolls for the virtue of coming early to the Friday prayer. However, a person will be recorded for the prayer, listening to the khutbah etc. by the two scribes who record his deeds.
Hafidh Ibn Hajr rahimahullah said:
“The [Hadith] indicates that the Angels mentioned [in the Hadith] are other than the Hafidah [the Angels who record the good and bad deeds]. The intent of the scrolls rolling up is the rolling up of the scrolls of virtue attached to coming early to the Jumu’ah unlike other than it from listening to the Khutbah, catching the prayer, the remembrance, the supplication, submissiveness and other than it for these actions will definitely be recorded by the two scribes”
Also Shaikh al-Albani rahimahullah mentions the following wording of the Hadith from Abu Hurairah (may Allah be pleased with him) reported by an-Nasaai:
من أدرك ركعة من الجمعة فقد أدرك الجمعة
Whoever catches one rak’ah of Jumu’ah, then he has caught the Jumu’ah
Shaikh al-Albani graded it authentic in [Ajwibah an-Naafi’ah (pg. 48-49)]
So that wording makes it clearer.
And Allah Knows Best
Faisal Ibn Abdul Qaadir Ibn Hassan