diff --git a/dd-java-agent/instrumentation/vertx/vertx-web/vertx-web-4.0/src/main/java/datadog/trace/instrumentation/vertx_4_0/server/HttpServerResponseEndHandlerInstrumentation.java b/dd-java-agent/instrumentation/vertx/vertx-web/vertx-web-4.0/src/main/java/datadog/trace/instrumentation/vertx_4_0/server/HttpServerResponseEndHandlerInstrumentation.java
index 5cfdf5767b2..d91e12e2835 100644
--- a/dd-java-agent/instrumentation/vertx/vertx-web/vertx-web-4.0/src/main/java/datadog/trace/instrumentation/vertx_4_0/server/HttpServerResponseEndHandlerInstrumentation.java
+++ b/dd-java-agent/instrumentation/vertx/vertx-web/vertx-web-4.0/src/main/java/datadog/trace/instrumentation/vertx_4_0/server/HttpServerResponseEndHandlerInstrumentation.java
@@ -34,7 +34,9 @@ public String[] helperClassNames() {
   @Override
   public String[] knownMatchingTypes() {
     return new String[] {
-      "io.vertx.core.http.impl.Http1xServerResponse", "io.vertx.core.http.impl.Http2ServerResponse "
+      "io.vertx.core.http.impl.Http1xServerResponse",
+      "io.vertx.core.http.impl.Http2ServerResponse",
+      "io.vertx.core.http.impl.HttpServerResponseImpl" // when v >= 5.1
     };
   }
 
diff --git a/dd-java-agent/instrumentation/vertx/vertx-web/vertx-web-4.0/src/main/java/datadog/trace/instrumentation/vertx_4_0/server/RouteHandlerWrapper.java b/dd-java-agent/instrumentation/vertx/vertx-web/vertx-web-4.0/src/main/java/datadog/trace/instrumentation/vertx_4_0/server/RouteHandlerWrapper.java
index c34fb32cdfb..70aaa687dde 100644
--- a/dd-java-agent/instrumentation/vertx/vertx-web/vertx-web-4.0/src/main/java/datadog/trace/instrumentation/vertx_4_0/server/RouteHandlerWrapper.java
+++ b/dd-java-agent/instrumentation/vertx/vertx-web/vertx-web-4.0/src/main/java/datadog/trace/instrumentation/vertx_4_0/server/RouteHandlerWrapper.java
@@ -8,6 +8,7 @@
 import static datadog.trace.instrumentation.vertx_4_0.server.VertxDecorator.DECORATE;
 import static datadog.trace.instrumentation.vertx_4_0.server.VertxDecorator.INSTRUMENTATION_NAME;
 
+import datadog.appsec.api.blocking.BlockingException;
 import datadog.context.ContextScope;
 import datadog.trace.bootstrap.instrumentation.api.AgentSpan;
 import datadog.trace.bootstrap.instrumentation.api.Tags;
@@ -65,6 +66,12 @@ public void handle(final RoutingContext routingContext) {
         actual.handle(routingContext);
       } catch (final Throwable t) {
         DECORATE.onError(span, t);
+        if (t instanceof BlockingException) {
+          // AppSec uses BlockingException as control flow after committing a blocking response
+          // from advice such as WafPublishingBodyHandler and RoutingContextJsonAdvice. Finish
+          // immediately because that abort path may bypass Vert.x response/routing end callbacks.
+          finishHandlerSpan(routingContext);
+        }
         throw t;
       }
     }
diff --git a/dd-java-agent/instrumentation/vertx/vertx-web/vertx-web-5.0/src/test/groovy/server/VertxHttpServerForkedTest.groovy b/dd-java-agent/instrumentation/vertx/vertx-web/vertx-web-5.0/src/test/groovy/server/VertxHttpServerForkedTest.groovy
index 8a9372dd9e7..2be39db6f4a 100644
--- a/dd-java-agent/instrumentation/vertx/vertx-web/vertx-web-5.0/src/test/groovy/server/VertxHttpServerForkedTest.groovy
+++ b/dd-java-agent/instrumentation/vertx/vertx-web/vertx-web-5.0/src/test/groovy/server/VertxHttpServerForkedTest.groovy
@@ -1,5 +1,6 @@
 package server
 
+import static datadog.trace.agent.test.base.HttpServerTest.ServerEndpoint.BODY_JSON
 import static datadog.trace.agent.test.base.HttpServerTest.ServerEndpoint.ERROR
 import static datadog.trace.agent.test.base.HttpServerTest.ServerEndpoint.EXCEPTION
 import static datadog.trace.agent.test.base.HttpServerTest.ServerEndpoint.LOGIN
@@ -16,6 +17,8 @@ import datadog.trace.instrumentation.netty41.server.NettyHttpServerDecorator
 import datadog.trace.instrumentation.vertx_4_0.server.VertxDecorator
 import io.vertx.core.AbstractVerticle
 import io.vertx.core.Vertx
+import okhttp3.MediaType
+import okhttp3.RequestBody
 
 class VertxHttpServerForkedTest extends HttpServerTest<Vertx> {
   @Override
@@ -181,4 +184,28 @@ class VertxHttpServerWorkerForkedTest extends VertxHttpServerForkedTest {
   HttpServer server() {
     return new VertxServer(verticle(), routerBasePath(), true)
   }
+
+  def 'test blocking of JSON request body finishes route handler span'() {
+    setup:
+    // VertxTestServer handles BODY_JSON by calling ctx.body().asJsonObject().
+    // The IG_BODY_CONVERTED_HEADER is consumed by HttpServerTest's AppSec test callback, which
+    // returns a RequestBlockingAction from requestBodyProcessed() when that JSON body is converted.
+    def request = request(
+      BODY_JSON, 'POST',
+      RequestBody.create(MediaType.get('application/json'), '{"a": "x"}'))
+      .header(IG_BODY_CONVERTED_HEADER, 'true')
+      .build()
+
+    when:
+    def response = client.newCall(request).execute()
+
+    then:
+    response.code() == 413
+    response.body().charStream().text.contains('"title":"You\'ve been blocked"')
+    !handlerRan
+    // The client receiving a 413 only proves the blocking response was committed.
+    // We want to make sure that a BlockingException does now abort the worker route handler
+    // before the vertx.route-handler span has been finished (which would leave it dangling)
+    TEST_WRITER.waitForTraces(1)
+  }
 }