The phrase "a narrow margin and" is correct and usable in written English.
It can be used when discussing a situation where there is a small difference or gap between two outcomes or results, often in a competitive context.
Example: "The election was decided by a narrow margin and highlighted the divided opinions within the community."
Alternatives: "a slim margin" or "a tight margin".
Ms. Park won the election by a narrow margin and was inaugurated in February.
Letta wins vote of confidence by a narrow margin and continues to govern Letta loses vote of confidence and Napolitano sets up a technical government.
Duarte won the election but creative recounting was done to give first place to Molina by a narrow margin and he was declared the victor.
The cyclists (protective headgear) bill was approved by the Northern Ireland assembly in January, albeit it by a narrow margin, and will now go before the Environment Committee.
In 1998 Havel was reelected by a narrow margin, and, under his presidency, the Czech Republic joined the North Atlantic Treaty Organization NATOO) in 1999.
It was clear to the Allies that this small-scale tactical experiment had missed success only by a narrow margin and that there was scope for its development.
Another will be to persuade people to vote for the EU's Nice treaty, which they rejected by a narrow margin a year ago and must be ratified by all 15 countries in the EU to let a dozen or so countries, mainly from Central Europe, join the club.
The ordinance was upheld by a narrow margin (289-282), and the new law immediately became enforceable.
Vice President Gore won by a relatively narrow margin, and a victory is, of course, better than a loss.
Warfarin, meanwhile, is the classic example of a drug with a narrow margin between therapeutic and toxic doses, requiring regular blood monitoring, and it can interact with many other drugs and foods.
Now, in its bulked-up state, the outdoor space is a narrow margin of sand and grass, not even wide enough to walk on.
