diff --git a/telethon/network/authenticator.py b/telethon/network/authenticator.py
index 7204433d..4414066c 100755
--- a/telethon/network/authenticator.py
+++ b/telethon/network/authenticator.py
@@ -11,6 +11,7 @@ def do_authentication(transport):
     """Executes the authentication process with the Telegram servers.
     If no error is rose, returns both the authorization key and the time offset"""
     sender = MtProtoPlainSender(transport)
+    sender.connect()
 
     # Step 1 sending: PQ Request
     nonce = os.urandom(16)
@@ -184,6 +185,9 @@ def do_authentication(transport):
 
     # Step 3 response: Complete DH Exchange
     with BinaryReader(sender.receive()) as reader:
+        # Everything read from the server, disconnect now
+        sender.disconnect()
+
         code = reader.read_int(signed=False)
         if code == 0x3bcbf734:  # DH Gen OK
             nonce_from_server = reader.read(16)
diff --git a/telethon/network/mtproto_plain_sender.py b/telethon/network/mtproto_plain_sender.py
index 1fa1fbc1..1721d2a3 100755
--- a/telethon/network/mtproto_plain_sender.py
+++ b/telethon/network/mtproto_plain_sender.py
@@ -12,8 +12,13 @@ class MtProtoPlainSender:
         self._time_offset = 0
         self._last_msg_id = 0
         self._transport = transport
+
+    def connect(self):
         self._transport.connect()
 
+    def disconnect(self):
+        self._transport.close()
+
     def send(self, data):
         """Sends a plain packet (auth_key_id = 0) containing the given message body (data)"""
         with BinaryWriter() as writer:
diff --git a/telethon/network/mtproto_sender.py b/telethon/network/mtproto_sender.py
index 15cbc287..5c31ded6 100644
--- a/telethon/network/mtproto_sender.py
+++ b/telethon/network/mtproto_sender.py
@@ -46,8 +46,6 @@ class MtProtoSender:
         self.updates_thread_sleep = None
         self.updates_thread = None  # Set later
 
-        self.connect()
-
     def connect(self):
         """Connects to the server"""
         self.transport.connect()
diff --git a/telethon/telegram_client.py b/telethon/telegram_client.py
index 32bd2c9b..d0e44a30 100644
--- a/telethon/telegram_client.py
+++ b/telethon/telegram_client.py
@@ -99,6 +99,7 @@ class TelegramClient:
                 self.session.save()
 
             self.sender = MtProtoSender(self.transport, self.session)
+            self.sender.connect()
 
             # Now it's time to send an InitConnectionRequest
             # This must always be invoked with the layer we'll be using