How it happened: The Sixers got a huge spark when coach Brett Brown inserted T.J. McConnell into the starting lineup and benched scuffling Robert Covington. McConnell finished with 19 points on 9-for-12 shooting, seven rebounds and five assists. Makes you wonder how different this series would have been had Brown stuck with McConnell at the end of Game 2, instead of taking him out for Ben Simmons.

What it means: There will be a Game 5 in Boston on Wednesday. Cleveland closed out its series against Toronto with a 128-93 win on Monday night, so the Sixers and Celtics will have an 8 p.m. start.

Heroes: Besides McConnell, Dario Saric (25 points, eight rebounds, four assists) had his best game of the series. Joel Embiid (15 points, 13 rebounds, two assists) was plus-22. He came in minus-8 through the first three games.

Never been a sweep. This is the 13th playoff series with Boston since the 76ers moved to Philadelphia from Syracuse in 1963-64. Boston has won eight, including the last three. The Sixers also were in 0-3 holes in 1969 and 1985 and lost the series five games each time. The last Sixers win over Boston was in 1982 in the "beat LA" series.

One down, three to go. No NBA team has ever overcome an 0-3 deficit in 129 series entering Monday. (The Sixers and Raptors entered Monday night each down 0-3.)  If the Sixers manage a win on Wednesday, Game 6 would be in Philadelphia. The pressure is squarely on the Celtics now.

Scare tactic. It was chippy all night, especially in the second quarter, which included Terry Rozier (6-1, 190) having to be separated from Joel Embiid (7-0, 260) a few minutes after Marcus Smart knocked off Embiid's mask with a hand to the face trying to strip the ball.

Boston Tech. Jaylen Brown and Brad Stevens picked up consecutive technical fouls, which Marco Belinelli converted, and Joel Embiid punctuated a flurry of offensive rebounds with a thunderous dunk to give the Sixers an 11-point lead late in the third quarter. Brown was particularly annoyed after picking up his fourth and fifth fouls within a couple of possessions.

Woe-Co: Robert Covington had another dismal game, but he did make a shot. Covington snapped an 0 for 12 with a fourth-quarter three-pointer. He was 0 for 8 in Game 3 and 0 for 6 in Game 1.

This and that. Something you don't see every day. Right after 90 percent shooter JJ Redick missed a pair of free throws, T.J. McConnell grabbed his own missed layup and put in the follow despite being a weed among all the Boston trees. The guy is just gritty … Jimmy Rollins, wearing a No. 25 Ben Simmons' jersey, rang the bell pregame. He sat next to Dikembe Mutombo during the game … Boston's Shane Larkin injured his left shoulder on a pick from Joel Embiid in the first quarter and did not return.