What happens as Romeo tries to enter Juliet's tomb?

Act V, Scene 3, when everything happens in the wrong order. There are 3 visitors to Juliet's tomb. They SHOULD have arrived in the following order: 1) Friar Lawrence, to wake Juliet up. 2) Romeo, to take her away to Mantua and live happily ever after. 3) Paris, to find that his fiancée had vaniched from the tomb. In fact they arrive in the reverse order: Paris comes first, and begins to mourn outside the tomb, when his Page warns him that somebody else is coming. Paris hides. Romeo arrives next, also with a servant (Balthasar) whom he dismisses before starting to open the tomb with a crowbar. Paris, not unnaturally, takes offence at a Montague vandalising the Capulet tomb, and fights him, which is a big mistake; we already know Romeo is quite handy with a sword. Romeo then enters the tomb, find Juliet apparently lifeless, swigs his poison, falls dead. FINALLY, Friar Lawrence arrives, Juliet wakes, the Friar very sensibly scarpers, and Juliet kills herself. It's all a question of timing; which is one reason why the purists will tell you that R&J, though very, very sad, is not in the classical sense a Tragedy, but rather a mere chapter of accidents.