diff --git a/site/docs/extensions/emphasis-extras.md b/site/docs/extensions/emphasis-extras.md
index 8c0ee64..6f4a5ce 100644
--- a/site/docs/extensions/emphasis-extras.md
+++ b/site/docs/extensions/emphasis-extras.md
@@ -60,6 +60,11 @@ This is ==highlighted== text.
 
 This is ==highlighted== text.
 
+An unmatched remainder of a closing delimiter run must not pull subsequent text
+into the emphasis. For example, `===a===== tail` renders as
+`=<mark>a===</mark> tail`. This example also round-trips unchanged with
+`EnableTrackTrivia()` and `RoundtripRenderer`.
+
 ## HTML output
 
 {.table}
diff --git a/src/Markdig.Tests/TestEmphasisRoundtrip.cs b/src/Markdig.Tests/TestEmphasisRoundtrip.cs
new file mode 100644
index 0000000..295df0c
--- /dev/null
+++ b/src/Markdig.Tests/TestEmphasisRoundtrip.cs
@@ -0,0 +1,83 @@
+// Copyright (c) Alexandre Mutel. All rights reserved.
+// This file is licensed under the BSD-Clause 2 license.
+// See the license.txt file in the project root for more information.
+
+using Markdig.Renderers.Roundtrip;
+using Markdig.Syntax;
+
+namespace Markdig.Tests;
+
+[TestFixture]
+public class TestEmphasisRoundtrip
+{
+    private static string RoundTrip(string markdown, MarkdownPipeline pipeline)
+    {
+        MarkdownDocument document = Markdown.Parse(markdown, pipeline);
+        var writer = new StringWriter();
+        var renderer = new RoundtripRenderer(writer);
+        pipeline.Setup(renderer);
+        renderer.Write(document);
+        return writer.ToString();
+    }
+
+    // Leftover delimiter characters below the minimum count used to stay nested
+    // inside the emphasis they closed, moving the following text to the end of
+    // the block. https://github.com/xoofx/markdig/issues/743
+    [Test]
+    public void GridTableSeparatorRoundtripsWithTrackTrivia()
+    {
+        string markdown =
+            "+---------------+---------------+--------------------+\n" +
+            "| Fruit         | Price         | Advantages         |\n" +
+            "+===============+===============+====================+\n" +
+            "| Bananas       | first line    | first line         |\n" +
+            "|               | next line     | next line          |\n" +
+            "+---------------+---------------+--------------------+\n";
+
+        var pipeline = new MarkdownPipelineBuilder()
+            .UseAutoLinks()
+            .UseEmphasisExtras()
+            .UseListExtras()
+            .EnableTrackTrivia()
+            .Build();
+
+        Assert.That(RoundTrip(markdown, pipeline), Is.EqualTo(markdown));
+    }
+
+    // Same defect, minimal: leftovers (15 = 7 * 2 + 1) below the "==" minimum.
+    [Test]
+    public void UnbalancedMarkedRunsRoundtrip()
+    {
+        string markdown = "+===============+===============+\n";
+
+        var pipeline = new MarkdownPipelineBuilder()
+            .UseEmphasisExtras()
+            .EnableTrackTrivia()
+            .Build();
+
+        Assert.That(RoundTrip(markdown, pipeline), Is.EqualTo(markdown));
+    }
+
+    [TestCase("===a===== tail\n", "<p>=<mark>a===</mark> tail</p>")]
+    [TestCase("===a==== tail\n", "<p>=<mark>a==</mark> tail</p>")]
+    [TestCase("=====a======= tail\n", "<p>=<mark><mark>a===</mark></mark> tail</p>")]
+    [TestCase("+++a+++++ tail\n", "<p>+<ins>a+++</ins> tail</p>")]
+    [TestCase("*===a===== tail*\n", "<p><em>=<mark>a===</mark> tail</em></p>")]
+    [TestCase("===a===== tail ==next==\n", "<p>=<mark>a===</mark> tail <mark>next</mark></p>")]
+    public void UnmatchedCloserPreservesTrailingContent(string markdown, string expectedHtml)
+    {
+        var pipeline = new MarkdownPipelineBuilder().UseEmphasisExtras().EnableTrackTrivia().Build();
+
+        Assert.That(RoundTrip(markdown, pipeline), Is.EqualTo(markdown));
+        Assert.That(Markdown.ToHtml(markdown, pipeline).Trim(), Is.EqualTo(expectedHtml));
+        Assert.That(Markdown.ToHtml(markdown, new MarkdownPipelineBuilder().UseEmphasisExtras().Build()).Trim(), Is.EqualTo(expectedHtml));
+    }
+
+    // The fix must not prevent balanced "marked" emphasis from being detected.
+    [Test]
+    public void BalancedMarkedEmphasisStillParses()
+    {
+        var pipeline = new MarkdownPipelineBuilder().UseEmphasisExtras().Build();
+        Assert.That(Markdown.ToHtml("==bold==", pipeline).Trim(), Is.EqualTo("<p><mark>bold</mark></p>"));
+    }
+}
diff --git a/src/Markdig/Parsers/Inlines/EmphasisInlineParser.cs b/src/Markdig/Parsers/Inlines/EmphasisInlineParser.cs
index 10fb4e3..bc0b08e 100644
--- a/src/Markdig/Parsers/Inlines/EmphasisInlineParser.cs
+++ b/src/Markdig/Parsers/Inlines/EmphasisInlineParser.cs
@@ -407,18 +407,33 @@ public class EmphasisInlineParser : InlineParser, IPostInlineProcessor
                             i--;
                         }
                     }
-                    else if ((closeDelimiter.Type & DelimiterType.Open) == 0)
-                    {
-                        closeDelimiter.ReplaceBy(closeDelimiter.AsLiteralInline());
-                        delimiters.RemoveAt(i);
-                        i--;
-                        break;
-                    }
                     else
                     {
+                        // Keep unmatched closers attached until their trailing content
+                        // has been moved out below.
                         break;
                     }
                 }
+
+                // Leftover delimiter characters keep the following inlines nested inside
+                // the emphasis; move them out so they keep their original position.
+                if (closeDelimiter.DelimiterCount > 0 && closeDelimiter.Parent is EmphasisInline closerParentEmphasis)
+                {
+                    var outermostEmphasis = closerParentEmphasis;
+                    while (outermostEmphasis.Parent is EmphasisInline ancestorEmphasis)
+                    {
+                        outermostEmphasis = ancestorEmphasis;
+                    }
+
+                    closeDelimiter.MoveChildrenAfter(outermostEmphasis);
+                }
+
+                if (closeDelimiter.DelimiterCount > 0 && (closeDelimiter.Type & DelimiterType.Open) == 0)
+                {
+                    closeDelimiter.ReplaceBy(closeDelimiter.AsLiteralInline());
+                    delimiters.RemoveAt(i);
+                    i--;
+                }
             }
         }