In February 1975, the police had their first major breakthrough.
The procedure was considered a major breakthrough in the medical field at the time.
"You told me yourself that Science is close to a major breakthrough."
Both times, then and now, a major breakthrough was close.
If the answer is positive, it would be a welcome step and major breakthrough.
Experts said the case could mark a major breakthrough in the treatment of cancer.
However, a major breakthrough came in the second season of the show, which he won.
By that time, he was already responsible for a major breakthrough.
You won't hear about it in the popular press until there's a major breakthrough.