diff --git a/src/mongo/db/repl/oplog.cpp b/src/mongo/db/repl/oplog.cpp
index ced1bff..8151e8c 100644
--- a/src/mongo/db/repl/oplog.cpp
+++ b/src/mongo/db/repl/oplog.cpp
@@ -614,47 +614,23 @@ namespace {
                 }
             }
             else {
-                // do upserts for inserts as we might get replayed more than once
-                OpDebug debug;
-                BSONElement _id;
-                if( !o.getObjectID(_id) ) {
-                    /* No _id.  This will be very slow. */
-                    Timer t;
-
-                    const NamespaceString requestNs(ns);
-                    UpdateRequest request(requestNs);
-
-                    request.setQuery(o);
-                    request.setUpdates(o);
-                    request.setUpsert();
-                    request.setFromReplication();
-                    UpdateLifecycleImpl updateLifecycle(true, requestNs);
-                    request.setLifecycle(&updateLifecycle);
-
-                    update(txn, db, request, &debug);
-
-                    if( t.millis() >= 2 ) {
-                        RARELY OCCASIONALLY log() << "warning, repl doing slow updates (no _id field) for " << ns << endl;
-                    }
+                uassert(ErrorCodes::NamespaceNotFound, str::stream() <<
+                        "Failed to apply insert due to missing collection: " << op.toString(),
+                        collection);
+
+                WriteUnitOfWork wuow(txn);
+                StatusWith<RecordId> status = collection->insertDocument( txn, o, true );
+
+                if (status.isOK()) {
+                    wuow.commit();
                 }
-                else {
-                    /* todo : it may be better to do an insert here, and then catch the dup key exception and do update
-                              then.  very few upserts will not be inserts...
-                              */
-                    BSONObjBuilder b;
-                    b.append(_id);
-
-                    const NamespaceString requestNs(ns);
-                    UpdateRequest request(requestNs);
-
-                    request.setQuery(b.done());
-                    request.setUpdates(o);
-                    request.setUpsert();
-                    request.setFromReplication();
-                    UpdateLifecycleImpl updateLifecycle(true, requestNs);
-                    request.setLifecycle(&updateLifecycle);
-
-                    update(txn, db, request, &debug);
+                else if (!status.isOK() && status.getStatus().code() != ErrorCodes::DuplicateKey) {
+                    log() << "skipping document duplicate key error during replicated insert: "
+                          << o.toString();
+
+                }
+                else if (!status.isOK()) {
+                    failedUpdate = true;
                 }
             }
         }