Hugo Grenier

In January, Grenier made his ATP Tour main draw debut at the 2021 Antalya Open, where he defeated Slovak qualifier Alex Molčan in straight sets before losing to fifth seed German Jan-Lennard Struff by walkover in the second round.[2] In November, Grenier won his first career ATP Challenger Tour singles title in Roanne, France.

He made his Grand Slam singles main draw debut as a lucky loser at the 2022 Wimbledon Championships where he earned his first career Grand Slam singles main draw match win and just his second career ATP Tour singles main draw match win by defeating fellow first-time qualifier Marc-Andrea Hüsler in five sets in a close-to-4-hours first round match.[3] He lost to the unseeded Cristian Garín in straight sets in the second round. Later in the month of July, he won his second career ATP Challenger Tour singles title at the 2022 Open Castilla y León dropping one set the whole week.[4]

In August, he made his US Open singles main draw debut, entering the main draw as a lucky loser. There, he beat Tomas Martin Etcheverry in the first round and lost to the 13th seed Matteo Berrettini in the second round. On 12 September, he broke into the top 100 of the ATP singles rankings at world No. 95 after winning the Cassis Open Provence singles title, defeating James Duckworth in the final.[5]

In March, Grenier won his fourth career Challenger singles title in Les Franqueses del Vallès, Spain.[6] Grenier made his ATP Tour singles main draw clay-court debut at the 2023 Grand Prix Hassan II. There, he was defeated in the final qualifying round by Dimitar Kuzmanov but entered the main draw as a lucky loser, where coincidentally he lost again to Kuzmanov in the first round.

Ranked No. 128 in the world, Grenier made his Masters 1000 singles main draw debut at the 2023 Mutua Madrid Open by winning two qualifying matches. In the main draw, he earned his first career ATP Tour singles main draw clay-court match win by defeating former top 10 player Diego Schwartzman in straight sets in the first round.[7][8] In the second round, he recorded his first career top 30 win by defeating 22nd seed Sebastian Korda in a straight sets match with two tiebreaks.[9] In the third round, he lost to 13th seed Alexander Zverev in straight sets 1-6, 0-6 in a 56-minute match.[10] Ranked No. 124, he entered the next Masters 1000 in Rome as a lucky loser but lost to J. J. Wolf in the first round.

He received a wildcard for the main draw at the 2023 French Open for his debut at this Major but lost in the first round.[11]

In July, Grenier won his fifth career Challenger singles title in Pozablanco, Spain, defeating Juan Pablo Ficovich in the final.[12] In October, Grenier reached the final in Alicante, Spain and lost to fellow countryman Constant Lestienne in the final for a second time at this tournament, the first time was in the final in 2021.