"When you don't take your chances against the No. 1 in the world, you are are in trouble", del Porto said.
Despite rain delaying his passage through to the final, Rafa Nadal has continued his incredible Roland Garros record by reaching yet another showpiece in France. He doesn't cede a thing and he doesn't let up.
Cecchinato's bid to become the spoiler's spoiler ended, for all intents and purposes, when he was unable to convert any of three set points in an entertaining second-set tiebreaker that was the middle chapter of Thiem's 7-5, 7-6 (10), 6-1 win.
This time, Thiem instead faced Cecchinato, a 25-year-old from Sicily who never had won a Grand Slam match until this tournament and was the lowest-ranked men's semifinalist at the clay-court major in 19 years. "I know I have to improve a little bit".
Thiem had too much, though, battling to take the first two sets and then cruising through the third to earn his shot at the title.
Del Potro insisted his hip had not troubled him during the match, instead putting the defeat down to one simple fact: "His game is too good for me".
It's a tactic Nadal has used more and more over the past year, mostly on clay and here at Roland Garros.
His opponent Friday will be Juan Martin del Potro, who got choked up after waiting almost a decade to return to the final four in Paris - and dealing with three wrist operations in the interim.
Yet Nadal, whose all-time claycourt record now stands at 414-36 says nobody should assume his feats are routine and that each victory is celebrated like the first.
"He's the big favourite against everybody and still I know how to play against him", Thiem said.More news: Trump, Trudeau swap jokes but hold firm in trade dispute
"It was a good second and third set for me, of course, and a good hold in the first", Nadal said afterward.
Nadal and Thiem have met nine times - all of them on clay.
And best of five sets is also a different story.
"If I want to beat him I have to play the way I did in Rome and in Madrid".
Only two players have managed to beat Nadal at the French Open since he first bounded into Roland Garros in 2005 armed with a bulging left bicep, pirate trousers and a pulverising brand of claycourt tennis the like of which had not been seen before. Stephens won last year's U.S. Open; Halep is 0-3 in major finals.
Del Potro's play this tournament, plus his history against Nadal - the fifth seed won two of their three previous duels and was the last foe to down the Mallorcan in a grand slam semifinal in 2009 - suggested a close tilt.
Cecchinato's career has been tainted by his involvement in a match-fixing scandal; he was banned for 18 months in 2016 before having the suspension overturned. He looks like he is nearly back to his best this season having picked up two titles, which includes winning his first Masters Series title with a three set win over Federer at Indian Wells.
"To beat him in five sets on clay is hard".
"It's hard to better the performance he had a year ago here", Moya said of Nadal's 2017 masterpiece.
Thiem weathered three set points for Cecchinato, at 7-6, 9-8 and 10-9. Thiem got to 10-all with a drop shot of his own.