The phrase "a growing lead over" is correct and usable in written English.
It can be used in contexts where one entity is gaining an advantage or superiority over another, often in competitive situations.
Example: "The team has established a growing lead over their rivals as the season progresses."
Alternatives: "an increasing advantage over" or "a widening gap over".
The flat tone of yesterday's statement is a plus for her, and is unlikely to affect her growing lead over Rick Lazio, her Republican challenger, as reflected in the latest New York Times/CBS poll.
She has a steadily growing delegate lead over Mr. Sanders in spite of his successes, because her margins of victory have been greater.
Leading a growing company is tough enough.
Research especially in the United Kingdom (UK) has led to a growing understanding of the situation of young carers over the last 15 years.
Fresh off of a post-convention bounce, Hillary Clinton is continuing to grow her lead over Donald Trump, according to new national polling released Thursday evening.
Over the years, budget restraints and a growing need for services have led to an increase in delays for rehabilitation in the province of Québec, Canada [ 3].
Though young people were never the Tories' core vote, these figures represent a steep drop from even 2015: in two years, the Labour party grew its lead over them by 19 points for 18 to 24-year-olds, and a staggering 26 points for 25 to 34-year-olds.
Empire grew its lead over Total Film, which was also up, 0.3% over the period to 85,981.
Netflix could grow its lead over Hulu through the US release of its Facebook app and the viral distribution it would receive through the news feed.
And it grew with an influx of a particular kind of voter; in that same time period, in Fairfax County alone, Democrats' lead over Republicans in Fairfax grew from three points to 15 points, according to election returns, with Obama garnering nearly 6 in 10 votes.
