The performance was an impressive.

Something that causes admiration or respect.
Her artwork is truly impressive.
The athlete's record-breaking run was impressive.
The building's architecture is impressive.
impressive performance
impressive results
impressive skills
awe-inspiring
remarkable
striking
The building is very impressive.

Causing admiration or respect because of size, quality, or skill.
Her performance was truly impressive.
The view from the mountain top is impressive.
He gave an impressive speech at the conference.
impressive results
impressive achievements
impressive performance
remarkable
awe-inspiring
striking
She gave an impressive speech.

Having a strong effect on someone; making a strong impression.
The movie had an impressive ending.
His artwork is truly impressive.
The athlete's performance was impressive.
impressive results
impressive achievements
impressive performance
striking
remarkable
notable