There’s nothing quite like sealing a tennis match with an ace: the kind that sends a stadium into a frenzy, like when Aryna Sabalenka faced that final in the AO, a crushing blow in Melbourne, or when Carlos Alcaraz closed out Jannik Sinner under the brightest lights at Arthur Ashe. But in Barcelona, something far more unexpected unfolded. Nuno Borges didn’t just win, he rewrote the ending, leaving a silence that felt louder than any roar.

Nuno Borges had already been pushed to the edge when Tomas Martin Etcheverry saved his first match point with a sharp return winner. The tension inside Pista Rafa Nadal tightened, and the next moment carried a different kind of weight. What followed caught everyone off guard.

Borges, serving under pressure and visibly struggling, chose a move that no one in the stadium saw coming. Etcheverry stood ready, expecting another conventional point. Instead, he was left frozen as the ball died quietly on the deuce court, out of reach before he could even react. The Argentine could only place his hands on his hips in disbelief. Borges had sealed a 6-3, 7-6 (3) victory in a way that stunned both his opponent and the crowd.

A quick handshake followed at the net, but the moment lingered. Soon after, Etcheverry withdrew from his doubles match with Corentin Moutet, bringing an abrupt end to his day. Borges’ decisive act was simple, yet controversial. He served underarm to win the final point with an ace, catching Etcheverry completely off guard.

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The reaction from the stands was mixed. Some fans took exception to the tactic, a reminder that the underarm serve still divides opinion in modern tennis. Yet the context matters.

Borges was struggling physically, battling cramps and even taking a medical time-out during the second set for treatment on his left thigh. He later told Portuguese journalist José Morgado that he was dealing with an issue in one of his legs.

In that moment, the choice was not just tactical but practical. He may not have been able to generate full power on a traditional serve, making the underarm option both clever and necessary. Still, no justification is truly required. In today’s game, where players often stand far behind the baseline to return, the underarm serve has become a legitimate surprise weapon.

Players like Alexander Bublik have mastered it, using it to disrupt rhythm and plant doubt in their opponents’ minds. It is no longer a novelty but a calculated risk. The evolution of the shot reflects broader changes in the sport. As return positions drifted deeper, something often seen with players like Rafael Nadal and taken to extremes by Daniil Medvedev, the underarm serve quietly found its place.

Etcheverry, who had recently pushed Carlos Alcaraz hard in Monte Carlo and defeated Jack Draper in Catalonia, arrived in strong form. That only made the ending more striking.

Now, Borges moves forward with momentum. He will face Hamad Medjedovic for a place in the Barcelona semifinals, carrying with him a moment that perfectly captures tennis at its most unpredictable.

Nick Kyrgios uses an underarm serve to beat Daniil Medvedev in Rome

Back in 2019, Nick Kyrgios delivered one of the most talked-about performances at the Italian Open. The unseeded Australian defeated Daniil Medvedev to reach the second round, using underarm serves on multiple occasions.

He made his intent clear from the very first point of the match. Kyrgios opened with an underarm serve, setting the tone for what would become a disruptive and unpredictable display. Despite the match going to three sets, he stayed committed to the tactic. It was not a one-off decision but a deliberate part of his approach.

That season, Kyrgios had already used similar tactics elsewhere. At the Mexican Open, he deployed underarm serves during his second-round win over Rafael Nadal. The reaction was immediate and critical.

Nadal said Kyrgios “lacks respect for the public, the rival and himself,” highlighting how controversial the shot remained. Kyrgios did not stop there. At the Miami Open, he again used the tactic, serving underarm twice in his 6-3 6-1 win over Dusan Lajovic.

Not everyone saw it negatively. Judy Murray described Kyrgios as a “genius” for using the shot to break his opponent’s rhythm. At its core, that is exactly what the underarm serve is designed to do. It disrupts timing, forces hesitation, and introduces doubt into the opponent’s mind.

Players themselves have explained its value. Alexander Bublik said at Wimbledon, “It’s just to mix it up, spice things up.”

He added further clarity. “It shouldn’t be a big deal — it’s just a stupid shot that gives another player an advantage. The chance you will hit it perfectly is like one or two in 10 and (if you don’t) you give the opponent an easy shot. But somehow no one is ready, so it’s tough. It’s just another shot.”

Even Medvedev, often on the receiving end, has acknowledged its place. “I used it sometimes myself. I think it’s a fair tactic.” 

As players like Nuno Borges now use it in crucial moments, the debate continues over whether it is controversial or simply smart tennis.