The Boston Celtics, a franchise steeped in unparalleled success and 18 championships, have just etched a painful new chapter into their storied history. In a stunning first-round exit, the Celtics became the first team in the organization’s 79-year existence to blow a 3-1 series lead, falling to the No. 7-seeded Philadelphia 76ers. What makes the collapse even more jarring is that head coach Joe Mazzulla accomplished something not even the much-maligned Doc Rivers managed during his tenure: squandering a commanding 3-1 advantage.
For a fanbase still reeling from the agony of Game 7, the loss represents more than just an early postseason departure—it marks a historic low for one of the NBA’s most decorated franchises. As Legion Hoops noted on X, this Celtics squad has now secured a dubious distinction that eluded even the Big Three era’s highs and lows.
Rivers’ Record vs. Mazzulla’s Milestone
Embed X: https://twitter.com/LegionHoops/status/2050761074727866786
Doc Rivers’ reputation has taken hits in the years since he left Boston, largely due to high-profile collapses with other teams. Yet during his time with the Celtics, Rivers never blew a 3-1 lead. His teams did, however, suffer several heartbreaking 3-2 leads that slipped away in seven games—losses that became emblematic of near-misses in the competitive Big Three era.
- In the 2009 Eastern Conference Semifinals against the Orlando Magic, the Celtics pushed the eventual Eastern Conference champions to the brink despite playing without an injured Kevin Garnett for much of the series (and losing Leon Powe as well). Orlando went on to defeat LeBron James and the Cavaliers in the next round.
- In the 2010 NBA Finals against the Los Angeles Lakers, Boston lost Kendrick Perkins to a devastating injury early in Game 6. They still forced a Game 7 but came up short.
- In the 2012 Eastern Conference Finals against the Miami Heat, the Celtics stunned the basketball world by taking a 3-2 lead over LeBron James, Dwyane Wade, and Chris Bosh. It took a historic performance from LeBron to eliminate them in seven.
In each of those series, Rivers and the Celtics had legitimate excuses rooted in significant injuries and the sheer talent on the opposing side. Mazzulla, by contrast, watched his fully healthy (or mostly healthy) roster for the majority of the series let a winnable matchup against a familiar foe slip through their fingers. While the absence of Jayson Tatum in Game 7 provided a final, cruel blow, it does not erase the earlier games where Boston failed to close out the series when opportunities were there. The collapse, in short, should never have reached that decisive seventh game.
A Coaching Catastrophe
This series stands as a stark indictment of Mazzulla’s coaching in the playoffs. Tactical decisions, player rotations, and in-game adjustments drew scrutiny as the Sixers mounted their improbable comeback. The loss carries extra weight because it came against a team the Celtics have dominated for nearly a decade.
Mazzulla now shares an infamous record with Rivers—not in the exact manner of the collapses, but in the broader narrative of postseason disappointment in Boston. Rivers at least delivered Banner 17 in 2008. Mazzulla’s seat, already under some pressure entering the postseason, is likely to feel noticeably warmer in the coming weeks. While a mid-series firing seems unlikely, this historic blown lead ensures the spotlight on his leadership will only intensify.
The Celtics’ rich history of success has long shielded the franchise from such ignominy. Blowing a 3-1 lead was something that simply didn’t happen in green. Until now.
For Boston fans still processing the pain of yesterday’s result, the numbers and historical context offer little comfort. This was supposed to be a team built for deeper runs. Instead, they delivered a collapse that will be discussed for years alongside the franchise’s most disappointing playoff moments. The question now is how the organization—and Mazzulla—responds to a failure that even Doc Rivers managed to avoid.