General Sani Abacha was the first serving officer in the Nigerian Armed Forces to attain the rank of 4-star general without skipping a rank. There had been other officers that attained the rank of 4 star general before him, but they all skipped ranks.
Yakubu Gowon was the first officer in the Nigerian Armed Forces to attain the rank of 4 star general, but he was promoted from the rank of lieutenant-colonel to the rank of major general on June 2nd, 1967 (at the start of the Civil War), skipping the ranks of colonel and brigadier general. He was double promoted again on October 1st 1971 to the rank of 4-star general (skipping the rank of lieutenant general).
Murtala Muhammed was the next officer to become a 4-star general, but he was promoted from the rank of brigadier to the rank of general (skipping the ranks of major general and lieutenant general) after becoming head of state.
The next officer to become a 4 star general was Olusegun Obasanjo. He was promoted from the rank of lieutenant general to general in April 1979. However, Obasanjo had been promoted from the rank of brigadier to the rank of lieutenant general (skipping the rank of major general) in 1975.
Similarly, President Ibrahim Babangida was promoted from the rank of major general to the rank of general (skipping the rank of lieutenant general) on October 1st, 1987.
Although General Domkat Bali did not skip any rank on his way to becoming a general, he was not in active service when he became a general. Bali was the longest serving military officer in Babangida’s administration (he was commissioned before Babangida). He became the minister of defence in 1984, when he held the rank of major general. He retained the position of minister of defence with the added title of chairman joint chiefs of staff after the August 27, 1985 coup. He was promoted to the rank of lieutenant general on October 1st, 1987.
However, on January 1st 1990, President Babangida moved General Bali to the position of minister of internal affairs (he also retired the chiefs of naval and air staff and the inspector general of police) and made lieutenant general Abacha the new minister of defence. General Bali retired from the army the next day. President Babangida accepted Bali’s retirement and promoted him to the rank of general. Therefore, General Bali was not in active service when he was promoted.
General Sani Abacha become the first officer in the Nigerian Armed Forces to be promoted to the rank of a 4-star general (without skipping a rank) in October 1990. General Abacha held the following ranks:
1963- Second lieutenant (commissioned)
1972- Lieutenant Colonel
1980- Brigadier General
1983- Major General
1987- Lieutenant General
Here is a picture of President Ibrahim Babangida and Vice President Augustus Aikhomu decorating General Abacha with his new rank in 1990.