Delete Duplicate Rows

declare @a1 table
(id int not null identity(1,1),
phone decimal(18,0),
adress nvarchar(100))
insert @a1
(phone,adress)

[Code] ....

id phone address
----------- --------------------------------------- ----------------------------------------------------------------------------------------------------
1 111 new york
2 111 new york
3 111 new york
4 222 maxico
5 222 mexico

select phone,count(phone) as say from @a1 group by phone having count(phone)>1

phone say
--------------------------------------- -----------
111 3
222 2

How can I remove duplicate phone. For example

after delete
select*from @a1
select*from @a1

id phone address
----------- --------------------------------------- ----------------------------------------------------------------------------------------------------
1 111 new york
4 222 maxico

I wrote this to show for example in my real table have 50000 rows and 1751 duplicate rows.

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