There is nothing wrong with you entering ihram for Hajj on the ninth day of Dhu’l-Hijjah and going directly to ‘Arafah. Your Hajj will be valid if you enter it between Zuhr and dawn of the tenth day. All of that is the time for standing in ‘Arafah, because of the report narrated by al-Tirmidhi (891), al-Nasaa’i (3039), Abu Dawood (1950) and Ibn Maajah (3016) from ‘Urwah ibn Mudarris al-Taa’i, who said: I came to the Messenger of Allah (blessings and peace of Allah be upon him) in Muzdalifah when he went out to pray [i.e., Fajr prayer]. I said: O Messenger of Allah, I have come from the two mountains of Tayyiy; I have exhausted my camel [because of the long journey] and I have worn myself out. By Allaah there is no sand hill on which I did not stand. Can I still do Hajj? The Messenger of Allah (blessings and peace of Allah be upon him) said: “Whoever attended this prayer of ours and stood with us until we moved on, and stood in ‘Arafah before that, by night or day, has completed his Hajj and completed his rituals.” Al-Tirmidhi said: This is a hasan saheeh hadeeth.
More than one of the scholars have narrated that there was consensus that the standing in Arafat continues until dawn on the Day of Sacrifice. Al-Nawawi (may Allah have mercy on him) said: The time for standing (in ‘Arafah) is between the time when the sun passes its zenith on the day of ‘Arafah and the break of dawn on the Day of Sacrifice. This is the view of Maalik, Abu Haneefah and the majority of scholars. Al-Qaadi Abu’l-Tayyib and al-‘Abdari said: This is the view of all the scholars except Ahmad who said: Its time is between dawn on the day of ‘Arafah and dawn on the Day of Sacrifice. End quote from al-Majmoo‘, 8/141
Ibn Qudaamah (may Allah have mercy on him) said: We do not know of any difference of opinion among the scholars with regard to the end of the standing being dawn on the Day of Sacrifice. Jaabir said: Hajj is not missed until dawn breaks on the day of Muzdalifah. Abu’l-Zubayr said: I said to him: did the Messenger of Allah (blessings and peace of Allah be upon him) say that? He said: Yes. It was narrated by al-Athram. With regard to its beginning, it starts at dawn on the day of ‘Arafah. So whoever reaches ‘Arafah at any point during this time, and is of sound mind, his Hajj is complete.
Maalik and al-Shaafa‘i said: The beginning of his time is when the sun passes its zenith on the day of ‘Arafah…
However the individual reaches Arafat, if he is of sound mind, that is acceptable, whether he is standing, sitting, riding or sleeping. Even if he passes by it without realizing that it is Arafat, that is also acceptable. This is the view of Maalik, al-Shaafa‘i and Abu Haneefah. End quote from al-Mughni, 3/211
For more information please see the answer to question no. 106581
Based on that, whenever the pilgrim reaches Arafat before dawn on the Day of Sacrifice, he has done Hajj and he has to perform the rest of the rituals.
We ask Allah to accept it from you.
And Allah knows best.