Fastest way to find a duplicate value in two large columns

Hi,

I need a comparison of values between two columns (10000 and 25000 rows)
I my case there will be one duplicate max.

I tried this with the Find function, but this still seems rather slow.

Sub Select_Duplicate_cells()
    Dim Rng As Range
    Dim I As Long
    Dim oCell As Range
    For Each oCell In Range("TableA[Col A]").Cells
        With Range("TableB[Col B]")
            Set Rng = .Find(What:=oCell.Value, _
                            After:=.Cells(.Cells.Count), _
                            LookIn:=xlFormulas, _
                            LookAt:=xlWhole, _
                            SearchOrder:=xlByRows, _
                            SearchDirection:=xlNext, _
                            MatchCase:=False)
            If Not Rng Is Nothing Then
                Debug.Print "Found! " & Rng.Address(False, False)
                Exit Sub
            End If
        End With
    Next oCell
End Sub

What would be the fasted way to compare the values and select the duplicate (so the Conditional Formatting solution does not work for me)?

No I have actually never used Match.
I see it is a worksheetfunction.
Do you have any idea how I would have to use this in this case?

I uploaded a test file.
I would like to retreive a cell reference from Col A where there is a match with values in Col B

Thanks for helping me out here...

Compare values in two columns.xlsb

Wow! What a huge difference !

With Find it takes 67 sec to find a match on row 6000
With your changes using Match it takes about 4 sec.

Btw, the double value was because of the testing, but I only need one match on a duplicate.

You've been a great help

Thanks very much !