DataRow.cs

public void Main()
{
	Mapper.Initialize(cfg =>
	{
		cfg.CreateMap<Source, Destination>();
		cfg.CreateMap<object, DataRow>().ConvertUsing((s, d)=>
		{
			foreach(var item in Mapper.Map<IDictionary<string, object>>(s))
			{
				d[item.Key] = item.Value;
			}
			return d;
		});
	});
	var table = new DataTable("x");
	table.Columns.Add("Value1");
	table.Columns.Add("Value2");
	table.Columns.Add("Value3");
	var dataRow = table.NewRow();
	Mapper.AssertConfigurationIsValid();
	Mapper.Map(new Source { Value = new Dto { Value1 = 1, Value2 = "2", Value3 = 3 }}, new Destination { Value = dataRow }).Dump();
}

class Dto
{
	public int Value1 { get; set; }
	public string Value2 { get; set; }
	public double Value3 { get; set; }
}

class Source
{
	public Dto Value { get; set; }
}

class Destination
{
	public DataRow Value { get; set; }
}

I had to use ConvertUsing((s, d, context) => and then call context.Mapper.Map