The phrase "a slender margin in" is correct and usable in written English.
It can be used to describe a small or narrow difference in a particular context, such as competition, performance, or measurement.
Example: "The team won the match by a slender margin in the final minutes, securing their place in the championship."
Alternatives: "a narrow margin in" or "a slight margin in".
Mr Obama is now ahead, by a slender margin, in Iowa, which in less than three weeks will be the first state to vote.
Mr. Dinkins, pledging to bring the city together again in a "gorgeous mosaic," narrowly defeated Mr. Koch in the primary and went on to beat Mr. Giuliani, who ran on the Republican and Liberal lines, by a slender margin in the general election.
Barber, 67, beat Republican rival Martha McSally by a slender margin in the Nov. 6 election to represent southeast Arizona in the state's redrawn 2nd Congressional District.
This was only the sixth one-wicket win in World Cup history, although such a slender margin of victory appeared unlikely in the extreme as Brendon McCullum flayed a 21-ball fifto to lead the Kiwi pursuit.
A hard-fought win over Francesco Moser in Italy saw him take the race with a slender margin of 1' 08" over the Italian who had pushed him every inch of the way by sprinting for every time bonus available.
Last year, in a referendum of their own, they decided, by a slender margin, not to become independent from the United Kingdom.
But an amendment tabled by Tory rebels proposed to cut the budget and, after Labour piled in to support it, the motion was carried by a slender margin.
But Lance, who comfortably secured re-election last year in a district that Democratic presidential nominee Hillary Clinton won by a slender margin over Trump, didn't have any easy night.
One percent is a slender margin of growth when it comes to feeding a global human population where at least one in seven people go hungry.
In fact, he managed only the middle one, which left his side ahead 6-3 at half-time, but only by a slender margin.
Three polls show the candidate of the governing party, Francisco Labastida Ochoa, leading by a slender margin.
