diff --git a/crates/render/src/paint.rs b/crates/render/src/paint.rs
index 6dd079f..13b4f4f 100644
--- a/crates/render/src/paint.rs
+++ b/crates/render/src/paint.rs
@@ -60,16 +60,7 @@ pub fn fill_path(
                     peniko::Gradient::new_linear(Point::new(c.x - dx * half, c.y - dy * half), Point::new(c.x + dx * half, c.y + dy * half))
                         .with_stops(stops.as_slice())
                 }
-                GradientShape::Path { focus, .. } => {
-                    let fx = bounds.x0 + bounds.width() * (focus[0] + (1.0 - focus[2])) / 2.0;
-                    let fy = bounds.y0 + bounds.height() * (focus[1] + (1.0 - focus[3])) / 2.0;
-                    // Reach the farthest corner, so a gradient from a corner covers the whole box.
-                    let r = [(bounds.x0, bounds.y0), (bounds.x1, bounds.y0), (bounds.x0, bounds.y1), (bounds.x1, bounds.y1)]
-                        .iter()
-                        .map(|(x, y)| ((x - fx).powi(2) + (y - fy).powi(2)).sqrt())
-                        .fold(1e-6, f64::max);
-                    peniko::Gradient::new_radial(Point::new(fx, fy), r as f32).with_stops(stops.as_slice())
-                }
+                GradientShape::Path { focus, .. } => circle_gradient(*focus, bounds).with_stops(stops.as_slice()),
             };
             ctx.set_paint(grad);
             ctx.fill_path(path);
@@ -116,19 +107,31 @@ pub fn gradient(shape: &GradientShape, mut stops: Vec<(f64, Rgba)>, bounds: Rect
             peniko::Gradient::new_linear(Point::new(c.x - dx * half, c.y - dy * half), Point::new(c.x + dx * half, c.y + dy * half))
                 .with_stops(stops.as_slice())
         }
-        GradientShape::Path { focus, .. } => {
-            let fx = bounds.x0 + bounds.width() * (focus[0] + (1.0 - focus[2])) / 2.0;
-            let fy = bounds.y0 + bounds.height() * (focus[1] + (1.0 - focus[3])) / 2.0;
-            // Reach the farthest corner, so a gradient from a corner covers the whole box.
-            let r = [(bounds.x0, bounds.y0), (bounds.x1, bounds.y0), (bounds.x0, bounds.y1), (bounds.x1, bounds.y1)]
-                .iter()
-                .map(|(x, y)| ((x - fx).powi(2) + (y - fy).powi(2)).sqrt())
-                .fold(1e-6, f64::max);
-            peniko::Gradient::new_radial(Point::new(fx, fy), r as f32).with_stops(stops.as_slice())
-        }
+        GradientShape::Path { focus, .. } => circle_gradient(*focus, bounds).with_stops(stops.as_slice()),
     }
 }
 
+/// A `circle` path gradient over `bounds` with focus rectangle `focus` (`fillToRect` insets, as
+/// fractions). As PowerPoint draws it (fitted to its exports): the first stop is a point at the
+/// focus (the middle of the focus rectangle) and the last is the circle around the whole box (its
+/// centre, half its diagonal), with circles in between moving from one to the other. A focus off
+/// the centre so bunches the colours on its near side; a gradient "from a corner" reaches its
+/// last colour at that corner too, not only at the far one.
+pub fn circle_gradient(focus: [f64; 4], bounds: Rect) -> peniko::Gradient {
+    let fx = bounds.x0 + bounds.width() * (focus[0] + (1.0 - focus[2])) / 2.0;
+    let fy = bounds.y0 + bounds.height() * (focus[1] + (1.0 - focus[3])) / 2.0;
+    let c = bounds.center();
+    let r = (bounds.width().hypot(bounds.height()) / 2.0).max(1e-6);
+    let f = Point::new(fx, fy);
+    if !(f.is_finite() && c.is_finite() && r.is_finite()) {
+        return peniko::Gradient::new_radial(c, r as f32);
+    }
+    // A focus on or outside the end circle has no circle through it: keep it just inside.
+    let d = f - c;
+    let f = if d.hypot() > r * 0.999 { c + d * (r * 0.999 / d.hypot()) } else { f };
+    peniko::Gradient::new_two_point_radial(f, 0.0, c, r as f32)
+}
+
 /// Draw a picture fill into `bounds` (shape-local) honouring crop and stretch/tile modes; an animated
 /// GIF shows its frame at `gif_time` seconds.
 pub fn picture(ctx: &mut RenderContext, pres: &Presentation, pf: &PictureFill, bounds: Rect, m: Affine, gif_time: Option<f64>) {
diff --git a/crates/render/src/tests_wild.rs b/crates/render/src/tests_wild.rs
index f817d8b..5f87c7a 100644
--- a/crates/render/src/tests_wild.rs
+++ b/crates/render/src/tests_wild.rs
@@ -161,3 +161,31 @@ fn trimming_a_path_leaves_its_ends_off_by_arc_length() {
     let r = Rect::new(0.0, 0.0, 10.0, 10.0).to_path(0.1);
     assert_eq!(trim_ends(&r, 3.0, 3.0).elements().len(), r.elements().len());
 }
+
+fn radial(focus: [f64; 4]) -> Shape {
+    use deckcraft_model::style::{Gradient, GradientShape, GradientStop};
+    let stops = vec![GradientStop { pos: 0.0, color: ColorRef::rgb(WHITE) }, GradientStop { pos: 1.0, color: ColorRef::rgb(Rgba::BLACK) }];
+    Shape {
+        id: ShapeId(13),
+        xfrm: Some(Xfrm::new(100.0, 100.0, 400.0, 200.0)),
+        fill: Some(Fill::Gradient(Gradient { stops, shape: GradientShape::Path { path: "circle".into(), focus }, rotate_with_shape: true })),
+        line: no_line(),
+        ..Default::default()
+    }
+}
+
+#[test]
+fn a_radial_gradient_off_centre_ends_on_the_circle_around_the_box() {
+    // Focus a fifth of the way in from the top-left corner. PowerPoint's last colour is reached on
+    // the circle through the box's corners, so the near corner is dark as well as the far one.
+    let img = render(vec![radial([0.2, 0.2, 0.8, 0.8])]);
+    assert!(img.pixel(181, 141)[0] > 240, "white at the focus {:?}", img.pixel(181, 141));
+    assert!(img.pixel(101, 101)[0] < 60, "near corner dark {:?}", img.pixel(101, 101));
+    assert!(img.pixel(498, 298)[0] < 60, "far corner dark {:?}", img.pixel(498, 298));
+    // Straight above the focus the box's edge is well inside the circle: still light.
+    assert!(img.pixel(181, 101)[0] > 150, "{:?}", img.pixel(181, 101));
+    // A centred one is symmetric, dark only at the corners.
+    let img = render(vec![radial([0.5, 0.5, 0.5, 0.5])]);
+    assert!(img.pixel(300, 200)[0] > 240 && img.pixel(101, 101)[0] < 60);
+    assert!((img.pixel(110, 200)[0] as i32 - img.pixel(490, 200)[0] as i32).abs() <= 2);
+}