"The way we let that one go really hurts" - Larry Bird admitted Celtics' morale took a big hit after dropping a clutch game in the 1987 finals

The Boston Celtics recognized that their best opportunity for securing a fourth championship in the 1980s presented itself in 1987 when they faced arch-rivals the LA Lakers in the NBA Finals.

Despite suffering substantial defeats in the first two games on the road, losing by 13 and 19 points, respectively, Larry Bird 's heroic performance in Game 3 managed to restore balance to the series. However, when the Celtics seemed confident, the Purple and Gold stormed back to register a nail-biting win in Game 4. Both Bird and Danny Ainge knew that the particular loss profoundly impacted the team internally.

Where did the Celtics lose the '87 Finals?

Given the 2-3-2 format followed in the championship round at the time, the C's remained optimistic after dropping the first two games at The Forum. Their first game at the Boston Garden saw the home team secure a 109-103 win, courtesy of all five starters scoring points in double digits and Larry Legend leading the charge with 30 points and 12 rebounds.

With momentum seemingly shifting in favor of Coach KC Jones' team, they appeared poised to level the series, building a substantial 16-point lead in the third quarter. Although Magic Johnson & Co. went on a late surge to close out the third quarter with only a 7-point deficit, they remained at a significant distance for much of the fourth quarter.

However, the tide turned dramatically when merely 3:30 remained on the clock, as the Lakers scored 12 of the game's 15 points to register a nail-biting 107-106 win. Witnessing his team lose the game in such a demoralizing fashion, Bird knew that his squad no longer possessed the same mental toughness as they once did.

"We've gotten beat here before, but the way we let that one go really hurts," Bird said . "Our mental toughness is just not what it used to be."

It wasn't just Larry who understood the significance of the Celtics' lackluster performance; even Ainge knew that if they lost the series, Game 4 would bear the most blame. Dennis Johnson also recognized that falling behind 3-1 made the task incredibly difficult, especially against the Lakers.

"It takes the night and most of the next day to realize what you did to yourself," Johnson said. "Now we have to win three straight, which is hard, and against the Lakers, it's probably three or four times harder."

Related: "He dunked on Perk so fu****g hard we had to stop practice" - Kevin Garnett on how the move to the G League motivated Avery Bradley

Bird knew the importance of games at home

The three-time MVP was aware of the Celtics' need to win all three games at home before returning to California. Even after Boston secured a 15-point win in Game 5, they never seemed confident before Game 6.

Having held a 5-point lead going into halftime, Boston's nerves broke in the third quarter. They scored merely 12 points, and the home team dropped 30. Ultimately, Kareem Abdul Jabbar's 32-point performance on 72.2% shooting from the field saw the Lakers win 106-93.

Related: "That's the obvious choice" - Don Nelson once compared Dirk Nowitzki to Larry Bird