diff --git a/tools/internal_ci/linux/grpc_xds_k8s_run_xtest.sh b/tools/internal_ci/linux/grpc_xds_k8s_run_xtest.sh
index 03dff0e7557..6f2a1c92614 100755
--- a/tools/internal_ci/linux/grpc_xds_k8s_run_xtest.sh
+++ b/tools/internal_ci/linux/grpc_xds_k8s_run_xtest.sh
@@ -64,8 +64,8 @@ find_oldest_branch() {
 #   Test xUnit report to ${TEST_XML_OUTPUT_DIR}/${test_name}/sponge_log.xml
 #######################################
 run_test() {
-  if [ "$#" -ne 4 ]; then
-    echo "Usage: run_test client_lang client_branch server_lang server_branch" >&2
+  if [ "$#" -ne 6 ]; then
+    echo "Usage: run_test client_lang client_branch server_lang server_branch cl-branch-fixed srv-branch-fixed" >&2
     exit 1
   fi
   # Test driver usage:
@@ -74,6 +74,8 @@ run_test() {
   local client_branch="$2"
   local server_lang="$3"
   local server_branch="$4"
+  local client_branch_fixed="$5"
+  local server_branch_fixed="$6"
   local server_image_name="${IMAGE_REPO}/${server_lang}-server"
   local client_image_name="${IMAGE_REPO}/${client_lang}-client"
 
@@ -87,9 +89,10 @@ run_test() {
   local server_image_name_tag="${server_image_name}:${server_branch}"
   local client_image_name_tag="${client_image_name}:${client_branch}"
 
-  local out_dir="${TEST_XML_OUTPUT_DIR}/${client_branch}-${server_branch}/${client_lang}-${server_lang}"
+  local out_dir="${TEST_XML_OUTPUT_DIR}/${client_branch_fixed}-${server_branch_fixed}/${client_lang}-${server_lang}"
   mkdir -pv "${out_dir}"
   set -x
+  echo "Client branch='${client_branch}', Server branch='${server_branch}'" > ${out_dir}/sponge_log.log
   python -m "tests.security_test" \
     --flagfile="${TEST_DRIVER_FLAGFILE}" \
     --kube_context="${KUBE_CONTEXT}" \
@@ -101,5 +104,5 @@ run_test() {
     --collect_app_logs \
     --log_dir="${out_dir}" \
     --xml_output_file="${out_dir}/sponge_log.xml" \
-    |& tee "${out_dir}/sponge_log.log"
+    |& tee -a "${out_dir}/sponge_log.log"
 }
diff --git a/tools/internal_ci/linux/grpc_xds_k8s_xbranch.sh b/tools/internal_ci/linux/grpc_xds_k8s_xbranch.sh
index 1eb6d713ed2..09204d88edb 100644
--- a/tools/internal_ci/linux/grpc_xds_k8s_xbranch.sh
+++ b/tools/internal_ci/linux/grpc_xds_k8s_xbranch.sh
@@ -75,25 +75,25 @@ main() {
   # Run cross branch tests per language: master x latest and master x oldest
   for LANG in ${LANGS}
   do
-    if run_test "${LANG}" "${MAIN_BRANCH}" "${LANG}" "${LATEST_BRANCH}"; then
+    if run_test "${LANG}" "${MAIN_BRANCH}" "${LANG}" "${LATEST_BRANCH}" "${MAIN_BRANCH}" "latest"; then
       successful_string="${successful_string} ${MAIN_BRANCH}-${LATEST_BRANCH}/${LANG}"
     else
       failed_tests=$((failed_tests + 1))
       failed_string="${failed_string} ${MAIN_BRANCH}-${LATEST_BRANCH}/${LANG}"
     fi
-    if run_test "${LANG}" "${LATEST_BRANCH}" "${LANG}" "${MAIN_BRANCH}"; then
+    if run_test "${LANG}" "${LATEST_BRANCH}" "${LANG}" "${MAIN_BRANCH}" "latest" "${MAIN_BRANCH}"; then
       successful_string="${successful_string} ${LATEST_BRANCH}-${MAIN_BRANCH}/${LANG}"
     else
       failed_tests=$((failed_tests + 1))
       failed_string="${failed_string} ${LATEST_BRANCH}-${MAIN_BRANCH}/${LANG}"
     fi
-    if run_test "${LANG}" "${MAIN_BRANCH}" "${LANG}" "${OLDEST_BRANCH}"; then
+    if run_test "${LANG}" "${MAIN_BRANCH}" "${LANG}" "${OLDEST_BRANCH}" "${MAIN_BRANCH}" "oldest"; then
       successful_string="${successful_string} ${MAIN_BRANCH}-${OLDEST_BRANCH}/${LANG}"
     else
       failed_tests=$((failed_tests + 1))
       failed_string="${failed_string} ${MAIN_BRANCH}-${OLDEST_BRANCH}/${LANG}"
     fi
-    if run_test "${LANG}" "${OLDEST_BRANCH}" "${LANG}" "${MAIN_BRANCH}"; then
+    if run_test "${LANG}" "${OLDEST_BRANCH}" "${LANG}" "${MAIN_BRANCH}" "oldest" "${MAIN_BRANCH}"; then
       successful_string="${successful_string} ${OLDEST_BRANCH}-${MAIN_BRANCH}/${LANG}"
     else
       failed_tests=$((failed_tests + 1))
diff --git a/tools/internal_ci/linux/grpc_xds_k8s_xlang.sh b/tools/internal_ci/linux/grpc_xds_k8s_xlang.sh
index 93922a06c27..cab473f7c6b 100755
--- a/tools/internal_ci/linux/grpc_xds_k8s_xlang.sh
+++ b/tools/internal_ci/linux/grpc_xds_k8s_xlang.sh
@@ -75,6 +75,7 @@ main() {
   OLDEST_BRANCH=$(find_oldest_branch "${OLDEST_BRANCH}" "${LATEST_BRANCH}")
   # Run cross lang tests: for given cross lang versions
   XLANG_VERSIONS="${MAIN_BRANCH} ${LATEST_BRANCH} ${OLDEST_BRANCH}"
+  declare -A FIXED_VERSION_NAMES=( ["${MAIN_BRANCH}"]="${MAIN_BRANCH}" ["${LATEST_BRANCH}"]="latest" ["${OLDEST_BRANCH}"]="oldest")
   for VERSION in ${XLANG_VERSIONS}
   do
     for CLIENT_LANG in ${CLIENT_LANGS}
@@ -82,7 +83,8 @@ main() {
     for SERVER_LANG in ${SERVER_LANGS}
     do
       if [ "${CLIENT_LANG}" != "${SERVER_LANG}" ]; then
-        if run_test "${CLIENT_LANG}" "${VERSION}" "${SERVER_LANG}" "${VERSION}"; then
+        FIXED="${FIXED_VERSION_NAMES[${VERSION}]}"
+        if run_test "${CLIENT_LANG}" "${VERSION}" "${SERVER_LANG}" "${VERSION}" "${FIXED}" "${FIXED}"; then
           successful_string="${successful_string} ${VERSION}/${CLIENT_LANG}-${SERVER_LANG}"
         else
           failed_tests=$((failed_tests+1))