Benfica stand on the brink of an extraordinary achievement—and a heartbreaking one. With just two matches remaining, the Eagles can complete the Primeira Liga season without a single defeat. But here's the catch: that undefeated record might not be enough to win the title.

Jose Mourinho's squad faces Braga on Monday night and Estoril Praia on the final day. Avoid losses in both, and they'll join an elite group of European clubs who've finished a league campaign invincible but empty-handed. It's a feat that's happened only seven times in European football history—and just twice this century.

Remarkably, this wouldn't be Benfica's first taste of such bittersweet history. Back in the 1977/78 season, they went unbeaten but watched rivals Porto snatch the title on goal difference after both teams finished level on 51 points. Porto had lost once but drew two fewer games, proving that perfection isn't always rewarded.

Benfica's 1972/73 Invincible season did bring them glory—they won the title that year. In fact, there have been four unbeaten campaigns in Primeira Liga history, but only one where the undefeated team didn't end up champions. That painful honor belongs to Benfica.

The agony of going unbeaten without silverware isn't unique to Portugal. A year after Benfica's near-miss, Italian side Perugia finished the 1978/79 Serie A season without losing—but drew 19 of 30 games. They finished as runners-up to AC Milan, a reminder that too many draws can be just as costly as defeats.

In more recent times, Red Star Belgrade went undefeated in the 2007/08 Serbian league but finished five points behind arch-rivals Partizan. And just last season, Moldova's FC Sheriff suffered no losses but still missed out to FC Milsami Orhei.

As Benfica prepares for these final two fixtures, they carry the weight of history—and the possibility of joining a very exclusive, very painful club. Whether they'll trade invincibility for victory remains to be seen.