diff --git a/dd-java-agent/instrumentation/aws-java/aws-java-lambda-handler-1.2/src/main/java/datadog/trace/instrumentation/aws/v1/lambda/LambdaHandlerInstrumentation.java b/dd-java-agent/instrumentation/aws-java/aws-java-lambda-handler-1.2/src/main/java/datadog/trace/instrumentation/aws/v1/lambda/LambdaHandlerInstrumentation.java
index d7407b47b5f..a945fabf647 100644
--- a/dd-java-agent/instrumentation/aws-java/aws-java-lambda-handler-1.2/src/main/java/datadog/trace/instrumentation/aws/v1/lambda/LambdaHandlerInstrumentation.java
+++ b/dd-java-agent/instrumentation/aws-java/aws-java-lambda-handler-1.2/src/main/java/datadog/trace/instrumentation/aws/v1/lambda/LambdaHandlerInstrumentation.java
@@ -24,6 +24,7 @@
 import datadog.trace.bootstrap.instrumentation.api.AgentSpanContext;
 import datadog.trace.bootstrap.instrumentation.api.AgentTracer;
 import datadog.trace.bootstrap.instrumentation.api.InternalSpanTypes;
+import datadog.trace.bootstrap.instrumentation.api.ResourceNamePriorities;
 import datadog.trace.config.inversion.ConfigHelper;
 import net.bytebuddy.asm.Advice;
 import net.bytebuddy.description.type.TypeDescription;
@@ -126,6 +127,21 @@ static void exit(
         String lambdaRequestId = awsContext.getAwsRequestId();
 
         AgentTracer.get().notifyAppSecEnd(span);
+        // Force the resource name back to the literal placeholder marker right
+        // before finish so that the Datadog Lambda Extension's filter
+        // (filter_span_from_lambda_library_or_runtime in
+        // bottlecap/src/traces/trace_processor.rs, which compares
+        // span.resource == "dd-tracer-serverless-span") drops the placeholder.
+        // Other instrumentation (HTTP/JAX-RS) may have overwritten it with the
+        // route ("POST /") during the invocation, in which case the extension
+        // would fail to dedup, leading to the placeholder leaking to the backend
+        // with parent_id=0 and detaching the inferred apigateway root from the
+        // rest of the trace.
+        // Use MANUAL_INSTRUMENTATION priority because DDSpanContext.setResourceName
+        // ignores writes whose priority is below the current resource priority,
+        // and the HTTP/JAX-RS instrumentation will already have written
+        // HTTP_FRAMEWORK_ROUTE (3) by this point.
+        span.setResourceName(INVOCATION_SPAN_NAME, ResourceNamePriorities.MANUAL_INSTRUMENTATION);
         span.finish();
         AgentTracer.get().notifyExtensionEnd(span, result, null != throwable, lambdaRequestId);
       } finally {