A few days back Nick Kyrgios, who isn’t playing at the US Open, posted a controversial tweet. No, not the one about Novak Djokovic but rather the opponent who progressed in his the infamous match: Pablo Carreno Busta.

In the now deleted tweet, Kyrgios took a swipe at the 2017 US Open finalist, saying that if the clay court didn’t exist Carreno Busta wouldn’t have even been close to the top 50. A rude as well as inaccurate remark, as many pointed out citing his numbers.

Whether the Spaniard was aware of this statement or no, it didn’t seem to matter as he played his version of effective, sustained tennis to reach the final four of a Grand Slam for the second time in his career. That he did it by beating prodigious 21-year-old Canadian Denis Shapovalov 3-6, 7-6, 7-6, 0-6, 6-3 in a match that lasted over four hours made it even starker.

“I’m destroyed, but I’m very, very happy,” the 20th seed said after the match. It sounded about right, given how hard-fought the win was in a roller-coaster five-setter.

This quarter-final was a clash of styles and generations even, as the Spaniard stuck to the basics against a player who possesses many tools with his lefty serve, one-handed backhand and enterprising game.

It may hard to define percentage tennis but easier to recognize it on court. The counter-punching, the grinding points, the side-to-side rallying were all the trademarks of solid textbook play and it worked out well for the winner.

Consider these statistics: Shapovalov has 76 winners to Carreno Busta’s 33. Shapovalov made 76 unforced errors to Carreno Busta’s 42. The difference in these numbers could well sum up the match.

The Canadian was all over the first set despite being broken early and then completely lost momentum on his serve in the second set. Yet, he fought bravely and pulled it to the tiebreak and that’s where Carreno Busta clutch execution triumphed over Shapovalov’s ideation.

The third set was similarly won in a tiebreak with efficient tennis and just when it seemed the Spaniard was one set away, the momentum completely shifted the other way. The 12th seed unleashed a flurry of winners to serve a bagel in the fourth set, during which Carreno Busta indicated he needed treatment.

After a medical time out before the decider, when it looked all done for him, Carreno Busta rediscovered his movement and started batting the ball back. For the first five games, both held serve for loss of just one point. Shapovalov, probably unprepared for such a turnaround at the other end, fumbled on his serve for one game and then committed the crime of a soluble fault on break point. That was all Carreno Busta needed. After four hours and eight minutes, the 29-year-old let out a loud ‘Vamos’ as he sealed a win.

On first look, it seemed that the experience of the oldest man standing trumped over the impulsiveness of youth. While that is true, there was more to this swinging result. It was a contrast in the way they play the game, why Shapovlov is considered one of the most watchable players while Carreno Busta flies under the radar. The youngster created more chances, took more risks and played an aggressive game. The veteran banked on his consistency, retrieving the balls and steadily chipping away at the attack with defence. While one style may gain more fans than the other, on the day the effective player was the one who didn’t try to do too much.

This is a quality that is sure to serve Carreno Busta well in his semi-final, taking on 23-year-old fifth seed Alexander Zverev. The German beat Borna Coric 1-6, 7-6 (7/5), 7-6 (7/1), 6-3 in a match that followed a similar pattern.

After going down 1-6, 2-4 against the Croatian who staged a great scape against Stefnaos Tsitispas, Zverev bounced back with a mix of steady, consistent tennis to reach his first US Open semi-final.

It was a big mental battle won and should have prepared him to face the defence of Carreno Busta. But as the 29-year-old showed, he can be unflappable in face of attack and win without trying to be flashy... a trait many younger players can learn from.

Both players are in their second Major final but Zverev was in the final four of this year’s Australian Open while it’s been three years since Busta lost to Kevin Anderson here, a player the fifth seed beat in the first round.

By all standards, Carreno Busta was an unexpected quarter-finalist given the controversial way he made it when world No 1 Djokovic was defaulted for hitting a line judge. But it would be unfair to call him a surprise semi-finalist.

His win percentage on hard courts is better than on clay and a second US Open semi-final after three years now gives him a chance to prove to detractors that even a steady game is fine as long as it gets the job done.