diff --git a/.chloggen/opamp_fix_27891_restart_delay.yaml b/.chloggen/opamp_fix_27891_restart_delay.yaml
new file mode 100644
index 000000000000..54c94f444048
--- /dev/null
+++ b/.chloggen/opamp_fix_27891_restart_delay.yaml
@@ -0,0 +1,27 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: bug_fix
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: opampsupervisor
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Fix restart delay when agent process exits unexpectedly.
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [27891]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:
+
+# If your change doesn't affect end users or the exported elements of any package,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: [user]
diff --git a/cmd/opampsupervisor/supervisor/commander/commander.go b/cmd/opampsupervisor/supervisor/commander/commander.go
index 90901e0e7103..7457f23693da 100644
--- a/cmd/opampsupervisor/supervisor/commander/commander.go
+++ b/cmd/opampsupervisor/supervisor/commander/commander.go
@@ -26,6 +26,7 @@ type Commander struct {
 	args    []string
 	cmd     *exec.Cmd
 	doneCh  chan struct{}
+	exitCh  chan struct{}
 	running *atomic.Int64
 }
 
@@ -39,6 +40,9 @@ func NewCommander(logger *zap.Logger, cfg *config.Agent, args ...string) (*Comma
 		cfg:     cfg,
 		args:    args,
 		running: &atomic.Int64{},
+		// Buffer channels so we can send messages without blocking on listeners.
+		doneCh: make(chan struct{}, 1),
+		exitCh: make(chan struct{}, 1),
 	}, nil
 }
 
@@ -52,6 +56,21 @@ func (c *Commander) Start(ctx context.Context) error {
 		return nil
 	}
 
+	// Drain channels in case there are no listeners that
+	// drained messages from previous runs.
+	if len(c.doneCh) > 0 {
+		select {
+		case <-c.doneCh:
+		default:
+		}
+	}
+	if len(c.exitCh) > 0 {
+		select {
+		case <-c.exitCh:
+		default:
+		}
+	}
+
 	c.logger.Debug("Starting agent", zap.String("agent", c.cfg.Executable))
 
 	logFilePath := "agent.log"
@@ -67,8 +86,6 @@ func (c *Commander) Start(ctx context.Context) error {
 	c.cmd.Stdout = logFile
 	c.cmd.Stderr = logFile
 
-	c.doneCh = make(chan struct{})
-
 	if err := c.cmd.Start(); err != nil {
 		return err
 	}
@@ -101,12 +118,13 @@ func (c *Commander) watch() {
 	}
 
 	c.running.Store(0)
-	close(c.doneCh)
+	c.doneCh <- struct{}{}
+	c.exitCh <- struct{}{}
 }
 
-// Done returns a channel that will send a signal when the Agent process is finished.
-func (c *Commander) Done() <-chan struct{} {
-	return c.doneCh
+// Exited returns a channel that will send a signal when the Agent process exits.
+func (c *Commander) Exited() <-chan struct{} {
+	return c.exitCh
 }
 
 // Pid returns Agent process PID if it is started or 0 if it is not.
diff --git a/cmd/opampsupervisor/supervisor/supervisor.go b/cmd/opampsupervisor/supervisor/supervisor.go
index 87ad84ba543e..49c2864fb101 100644
--- a/cmd/opampsupervisor/supervisor/supervisor.go
+++ b/cmd/opampsupervisor/supervisor/supervisor.go
@@ -797,7 +797,7 @@ func (s *Supervisor) runAgentProcess() {
 			s.stopAgentApplyConfig()
 			s.startAgent()
 
-		case <-s.commander.Done():
+		case <-s.commander.Exited():
 			if s.shuttingDown {
 				return
 			}
@@ -817,7 +817,12 @@ func (s *Supervisor) runAgentProcess() {
 			// https://github.com/open-telemetry/opentelemetry-collector-contrib/issues/21079
 
 			// Wait 5 seconds before starting again.
-			restartTimer.Stop()
+			if !restartTimer.Stop() {
+				select {
+				case <-restartTimer.C: // Try to drain the channel
+				default:
+				}
+			}
 			restartTimer.Reset(5 * time.Second)
 
 		case <-restartTimer.C: