TeeChart. Draw grid lines on the top of Gantt series

I am using Gantt series to show regions on a chart. The problem is that the series is drawn on the top of the chart grid.

I would like the normal line series to be drawn on the top of the grid and Gantt series behind it. Is it possible with standard TChart features, without OnAfterDraw?

You could draw the TGanttSeries at OnBeforeDrawAxes, then hide it at OnBeforeDrawSeries and finally make it visible again at OnAfterDraw for the next drawing cycle:

type
  TForm1 = class(TForm)
    Chart1: TChart;
    Series1: TGanttSeries;
    Series2: TLineSeries;
    procedure FormCreate(Sender: TObject);
    procedure Chart1BeforeDrawAxes(Sender: TObject);
    procedure Chart1BeforeDrawSeries(Sender: TObject);
    procedure Chart1AfterDraw(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

type TCustomSeriesAccess=class(TCustomSeries);

procedure TForm1.Chart1BeforeDrawAxes(Sender: TObject);
begin
  TCustomSeriesAccess(Series1).DrawAllValues;
end;

procedure TForm1.Chart1BeforeDrawSeries(Sender: TObject);
begin
  Series1.Visible:=False;
end;

procedure TForm1.Chart1AfterDraw(Sender: TObject);
begin
  Series1.Visible:=True;
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  Chart1.Draw;
end;