Biggest Final 4 Playoff upsets in NBA history?

[3Peatkb24]

If the Warriors lose to the Thunder where would it rank? Here are the choices:
Warriors/Thunder 2016 WCFinals - Warriors have HCA and could lose?
Heat/Mavs 2011 Finals - Heat had HCA but lost
Cavs/Magic 2009 ECFinals - Cavs had HCA but lost
Lakers/Pistons 2004 Finals - Lakers had HCA but lost
Lakers/Rockets 1986 WCFinals - Lakers had HCA but lost
Sixers/Blazers 1977 Finals - Sixers had HCA but lost
Lakers/Celtics 1969 Finals - Lakers had HCA but lost
-You can only choose one!

[KobeMVP888]

The first one that came to mind was the 2009 ECF. The Cavs were 66-16 and only lost two games at home all season, the first against us and the second when they rested everyone on the last game of the season. Then the Dwight Howard led Magic stunned them in Game 1 in Cleveland and the series took on the same pattern as this one. It's actually a great analogy should the Thunder win this thing because the #3 seed Magic knocked off the #2 seed Chowds, who won 62 games before defeating the #1 seed Cavs.

HAVING SAID THAT, it ain't over 'til it's over. This series can still flip.

[3Peatkb24]

The first one that came to mind was the 2009 ECF. The Cavs were 66-16 and only lost two games at home all season, the first against us and the second when they rested everyone on the last game of the season. Then the Dwight Howard led Magic stunned them in Game 1 in Cleveland and the series took on the same pattern as this one. It's actually a great analogy should the Thunder win this thing because the #3 seed Magic knocked off the #2 seed Chowds, who won 62 games before defeating the #1 seed Cavs.

HAVING SAID THAT, it ain't over 'til it's over. This series can still flip.

I still think us losing to the Rockets in 1986 was the most stunning thing I have ever seen but I may think like that because I was only 15 years old and thought the Lakers were invincible back then. I remember after Ralph beat us with that funky shot I couldn't sleep and went to school on no sleep! I remember my mom waking up to go to work at 445 am in the morning like always and walking out into the living room, saying Mikey what in the hell are you still doing up it's almost 5, you have school in 3 hours. I responded by saying the Lakers lost, she said when is the next game, I said there isn't one the season is over. I will say this the 2009 ECFinals absolutely stunned me as well. That was when LeBron first started dominating and they were unbeatable at home. The Cavs had a decent team around him as well and that was when LeBron was at his best. When they lost Game 1 I couldn't believe it. I still thought it was a fluke and the Cavs would roll but they didn't, Once Dwight and those 3 point shooters got to Orlando it was a rap!