Unit testing async method for specific exception

Does anyone have an example of how to unit test an async method in a Windows 8 Metro application, to ensure that it throws the required exception?

Given a class with an async method

public static class AsyncMathsStatic
{
    private const int DELAY = 500;

    public static async Task<int> Divide(int A, int B)
    {
        await Task.Delay(DELAY);
        if (B == 0)
            throw new DivideByZeroException();
        else
            return A / B;
    }
}

I want to write a test method using the new Async.ExpectsException construction. I've tried :-

[TestMethod]
public void DivideTest1()
{
    Assert.ThrowsException<DivideByZeroException>(async () => { int Result = await AsyncMathsStatic.Divide(4, 0); });
}

but of course the test doesn't wait for the async method to complete, and so results in a failed test that the exception hasn't been thrown.