diff --git a/go/ast/astutil/imports.go b/go/ast/astutil/imports.go
index 4a77c782..83f196cd 100644
--- a/go/ast/astutil/imports.go
+++ b/go/ast/astutil/imports.go
@@ -49,6 +49,8 @@ func AddNamedImport(fset *token.FileSet, f *ast.File, name, ipath string) (added
 		lastImport = -1         // index in f.Decls of the file's final import decl
 		impDecl    *ast.GenDecl // import decl containing the best match
 		impIndex   = -1         // spec index in impDecl containing the best match
+
+		isThirdPartyPath = isThirdParty(ipath)
 	)
 	for i, decl := range f.Decls {
 		gen, ok := decl.(*ast.GenDecl)
@@ -65,15 +67,27 @@ func AddNamedImport(fset *token.FileSet, f *ast.File, name, ipath string) (added
 				impDecl = gen
 			}
 
-			// Compute longest shared prefix with imports in this group.
+			// Compute longest shared prefix with imports in this group and find best
+			// matched import spec.
+			// 1. Always prefer import spec with longest shared prefix.
+			// 2. While match length is 0,
+			// - for stdlib package: prefer first import spec.
+			// - for third party package: prefer first third party import spec.
+			// We cannot use last import spec as best match for third party package
+			// because grouped imports are usually placed last by goimports -local
+			// flag.
+			// See issue #19190.
+			seenAnyThirdParty := false
 			for j, spec := range gen.Specs {
 				impspec := spec.(*ast.ImportSpec)
-				n := matchLen(importPath(impspec), ipath)
-				if n > bestMatch {
+				p := importPath(impspec)
+				n := matchLen(p, ipath)
+				if n > bestMatch || (bestMatch == 0 && !seenAnyThirdParty && isThirdPartyPath) {
 					bestMatch = n
 					impDecl = gen
 					impIndex = j
 				}
+				seenAnyThirdParty = seenAnyThirdParty || isThirdParty(p)
 			}
 		}
 	}
@@ -175,6 +189,12 @@ func AddNamedImport(fset *token.FileSet, f *ast.File, name, ipath string) (added
 	return true
 }
 
+func isThirdParty(importPath string) bool {
+	// Third party package import path usually contains "." (".com", ".org", ...)
+	// This logic is taken from golang.org/x/tools/imports package.
+	return strings.Contains(importPath, ".")
+}
+
 // DeleteImport deletes the import path from the file f, if present.
 func DeleteImport(fset *token.FileSet, f *ast.File, path string) (deleted bool) {
 	return DeleteNamedImport(fset, f, "", path)
diff --git a/go/ast/astutil/imports_test.go b/go/ast/astutil/imports_test.go
index 21682674..8bc34808 100644
--- a/go/ast/astutil/imports_test.go
+++ b/go/ast/astutil/imports_test.go
@@ -140,6 +140,95 @@ import (
 
 	"d/f"
 )
+`,
+	},
+	{
+		name: "issue #19190",
+		pkg:  "x.org/y/z",
+		in: `package main
+
+// Comment
+import "C"
+
+import (
+	"bytes"
+	"os"
+
+	"d.com/f"
+)
+`,
+		out: `package main
+
+// Comment
+import "C"
+
+import (
+	"bytes"
+	"os"
+
+	"d.com/f"
+	"x.org/y/z"
+)
+`,
+	},
+	{
+		name: "issue #19190 with existing grouped import packages",
+		pkg:  "x.org/y/z",
+		in: `package main
+
+// Comment
+import "C"
+
+import (
+	"bytes"
+	"os"
+
+	"c.com/f"
+	"d.com/f"
+
+	"y.com/a"
+	"y.com/b"
+	"y.com/c"
+)
+`,
+		out: `package main
+
+// Comment
+import "C"
+
+import (
+	"bytes"
+	"os"
+
+	"c.com/f"
+	"d.com/f"
+	"x.org/y/z"
+
+	"y.com/a"
+	"y.com/b"
+	"y.com/c"
+)
+`,
+	},
+	{
+		name: "issue #19190 - match score is still respected",
+		pkg:  "y.org/c",
+		in: `package main
+
+import (
+	"x.org/a"
+
+	"y.org/b"
+)
+`,
+		out: `package main
+
+import (
+	"x.org/a"
+
+	"y.org/b"
+	"y.org/c"
+)
 `,
 	},
 	{
diff --git a/imports/fix_test.go b/imports/fix_test.go
index ffab3907..89c7e7bc 100644
--- a/imports/fix_test.go
+++ b/imports/fix_test.go
@@ -800,6 +800,70 @@ import (
 )
 
 var _ = fmt.Sprintf
+`,
+	},
+
+	{
+		name: "issue #19190 1",
+		in: `package main
+
+import (
+	"time"
+)
+
+func main() {
+	_ = snappy.Encode
+	_ = p.P
+	_ = time.Parse
+}
+`,
+		out: `package main
+
+import (
+	"time"
+
+	"code.google.com/p/snappy-go/snappy"
+	"rsc.io/p"
+)
+
+func main() {
+	_ = snappy.Encode
+	_ = p.P
+	_ = time.Parse
+}
+`,
+	},
+
+	{
+		name: "issue #19190 2",
+		in: `package main
+
+import (
+	"time"
+
+	"code.google.com/p/snappy-go/snappy"
+)
+
+func main() {
+	_ = snappy.Encode
+	_ = p.P
+	_ = time.Parse
+}
+`,
+		out: `package main
+
+import (
+	"time"
+
+	"code.google.com/p/snappy-go/snappy"
+	"rsc.io/p"
+)
+
+func main() {
+	_ = snappy.Encode
+	_ = p.P
+	_ = time.Parse
+}
 `,
 	},
 }