Russian word сразу comes from Russian раз, Russian с

Detailed word origin of сразу

Dictionary entry	Language	Definition
раз	Russian (rus)	One (in counting). Time (an instance or occurrence) (colloquial) since; as long as (colloquial) once, one day, once upon a time.
с	Russian (rus)	Centi- (0.01) (for indicating a duration of time; used in two forms: с +genitive по +accusative and с +genitive до +genitive). (for time expressions). Because of, since (expressing a cause of motivation) (+ genitive case). For, about (indefinite time or number) (+ accusative case). From, off, from off, from below (with abstract nouns; nouns entailing a flat, open area; and special [...]
сразу	Russian (rus)	At once, right away, straight away. At once, simultaneously. At one stroke. Straight off, out of hand.