Here are some observations after the Sixers' 101-98 loss to the Celtics on Saturday:

⋅ What it means. The Sixers are in a world of trouble. No NBA team has ever come back from being down three games to none in a series. The Sixers committed critical turnovers at the worst time and have to avoid being swept on Monday.

⋅ Marco de Mayo. Marco Belinelli hit a buzzer-beater to send the game into overtime in one of the wildest sequences to end a Sixers-Celtics game, which is saying something. He hoisted another prayer at the end of overtime that did not go in.

⋅ JJ's gaffe. The Sixers have found some creative ways to lose to the Celtics, but this was ALMOST a doozy. Waning seconds. Tied game at 87 when JJ Redick threw the ball to Ben Simmons, who wasn't looking. Terry Rozier picked up the loose ball, sprinted down the court and handed it to Jaylen Brown for a layup. It sure looked like the Celtics won in regulation. But Al Horford made a steal late in the overtime and hit the clinching free throws.

⋅ Two minutes for roughing. It was as physical as a hockey game out there tonight highlighted by constant battling in the post. Joel Embiid and Aron Baynes were the most notable combatants.

Embiid had one of those career highlight plays when he took a behind-the-back pass from Simmons in transition and dunked emphatically over Celtics center Aron Baynes, who unsuccessfully tried to draw a charge. It probably won't reach the legendary status the Doc's rock-the-baby dunk over Michael Cooper, but it was just as nasty.

⋅ Ben's night. Simmons was much more involved in Game 3 than he was Thursday night, though the mistakes were critical. Simmons had 16/8/8, but he also missed a wide-open dunk midway through the fourth quarter with the game tied at 81. And his decision to shoot after grabbing an offensive rebound with 18 seconds left in overtime was silly. The Sixers were up one. Simmons should have kicked the ball out and forced Boston to foul. He also had several bad inbounds passes, including one with less than four seconds that was stolen by the Celtics.

⋅ Where'd ya go? Robert Covington struggled Saturday night. He went 0 for 8 from the field, hanging his head after one of his five misses from three. He scored one point and was a minus-10 in just 25 minutes of play. It's the second time in the series Covington has disappeared. He had just three points and was a minus-13 in Game 1. He had 22 points (plus-4) in Game 2.