# Lukáš Klein

Lukáš Klein (born 22 March 1998) is a Slovak professional tennis player. Klein has a career-high ATP singles ranking of world No. 109, achieved on 5 August 2024. He also has a career-high doubles ranking of No. 240, achieved on 5 April 2021. He is currently the No. 2 Slovak tennis player in singles.
Klein has reached 15 career singles finals, with a record of 9 wins and 6 losses, including 3 ATP Challenger titles. Additionally, he has reached 11 career doubles finals, with a record of 5 wins and 6 losses, including a 1–3 result in Challenger finals.

## Career
### 2021: ATP & top 250 & Olympics debut

Klein won the doubles title at the 2021 Challenger La Manche with compatriot Alex Molčan 1–6, 7–5, [10–6].
Klein made his ATP main draw singles debut in March at the 2021 Argentina Open, where he defeated Andrea Collarini, Thiago Seyboth Wild and Ernesto Escobedo to qualify for the main draw. Klein then went on to upset compatriot Andrej Martin in straight sets. He would go on to lose in the second round to top seed, local favourite and eventual champion Diego Schwartzman in straight sets.
He reached the top 250 at World No. 248 in singles on 28 June 2021 after reaching the second round also as a qualifier at the 2021 Mallorca Championships by defeating 8th seed Dušan Lajović, for his second ATP win for the season and in his career.
At the Olympics, Klein was entered as an alternate for Matteo Berrettini, who had withdrawn due to a thigh injury. He also participated in the doubles event partnering Filip Polášek and reaching the second round.

### 2022: First Challenger title, top 150 debut

In May, he won his first Challenger at the 2022 Saturn Oil Open in Troisdorf, Germany as a qualifier without dropping a set.
He qualified for the 2022 Wimbledon Championships making his Grand Slam debut. He lost to wildcard Liam Broady in five sets.
He reached his second Challenger final in Alicante and won the title. As a result, he moved more than 40 positions up to a new career-high in the top 180 on 10 October 2022. Following his third final in Ortisei, Italy he moved 17 positions up into the top 150 at No. 146 on 31 October 2022.

### 2023-25: First Major and Masters wins, Slovak No. 1

He qualified for and reached back-to-back finals at the 2023 Sparkassen ATP Challenger in Ortisei, Italy. He won his third Challenger title defeating Maks Kaśnikowski.
In January 2024, he qualified for the 2024 Brisbane International and defeated sixth seed Sebastián Báez for his first ATP win of the season and only third in his career. Ranked No. 163, he qualified for the 2024 Australian Open making his debut at this tournament and recorded his first Major win over Kwon Soon-woo. In the next round, he took sixth seed Alexander Zverev to five sets before losing the match in a fifth set tiebreak.
He qualified for the 2024 BNP Paribas Open making his Masters debut and recorded his first win at this level over Nicolas Moreno de Alboran. As a result he moved to a new career high in the top 130 and became the Slovak No. 1 player. Next he qualified for another Masters, the 2024 Miami Open defeating Benoit Paire and Jakub Menšík. He lost to Alex Michelsen in the first round. As a result he reached the top 120 in the rankings at world No. 116 on 1 April 2024.
He qualified for his third Masters of the season at the 2024 Mutua Madrid Open and recorded his first win at the tournament and only second at this level, over fellow qualifier Pablo Llamas Ruiz before losing to 15th seed Tommy Paul.

## Performance timelines

Key :
| W | F | SF | QF | #R | RR | Q# | P# | DNQ | A | Z# | PO | G | S | B | NMS | NTI | P | NH |

### Singles

| Tournament | 2020 | 2021 | 2022 | 2023 | 2024 | W–L | Win % |
| Grand Slam tournaments | Grand Slam tournaments | Grand Slam tournaments | Grand Slam tournaments | Grand Slam tournaments | Grand Slam tournaments | Grand Slam tournaments | |
| Australian Open | A | A | A | Q1 | 2R | 1–1 | 50% |
| French Open | A | A | A | Q2 | Q1 | 0–0 | – |
| Wimbledon | NH | A | 1R | Q2 | Q2 | 0–1 | 0% |
| US Open | A | A | A | Q3 | Q1 | 0–0 | – |
| Win–loss | 0–0 | 0–0 | 0–1 | 0–0 | 1–1 | 1–2 | 33% |
| ATP Masters 1000 tournaments | ATP Masters 1000 tournaments | ATP Masters 1000 tournaments | ATP Masters 1000 tournaments | ATP Masters 1000 tournaments | ATP Masters 1000 tournaments | ATP Masters 1000 tournaments | |
| Indian Wells Masters | NH | A | A | A | 2R | 1–1 | 50% |
| Miami Open | NH | A | A | Q2 | 1R | 0–1 | 0% |
| Monte-Carlo Masters | NH | A | A | A | A | 0–0 | – |
| Madrid Open | NH | A | A | Q1 | 2R | 1–1 | 50% |
| Italian Open | A | A | A | A | A | 0–0 | – |
| Canadian Open | NH | A | A | A | | 0–0 | – |
| Cincinnati Masters | A | A | A | A | | 0–0 | – |
| Shanghai Masters | NH | NH | NH | A | | 0–0 | – |
| Paris Masters | A | A | A | A | | 0–0 | – |
| Win–loss | 0–0 | 0–0 | 0–0 | 0–0 | 2–3 | 2–3 | 40% |
| Career statistics | Career statistics | Career statistics | Career statistics | Career statistics | Career statistics | Career statistics | |
| | 2020 | 2021 | 2022 | 2023 | 2024 | Career | |
| Tournaments | 0 | 3 | | | | | |
| Titles / Finals | 0 / 0 | 0 / 0 | 0 / 0 | 0 / 0 | 0 / 0 | 0 / 0 | |
| Overall win–loss | 0–0 | 2–4 | 0–1 | 0–3 | 5–5 | 7–13 | 35% |
| Year-end ranking | | | | | | | |

## ATP Challenger and ITF Tour finals
### Singles: 15 (9–6)

* Legend
* ATP Challenger (3–2)
* ITF Futures (6–4)
* Finals by surface
* Hard (6–2)
* Clay (3–3)
* Grass (0–0)
* Carpet (0–1)
| Result | W–L | Date | Tournament | Tier | Surface | Opponent | Score |
| Loss | 0–1 | Aug 2017 | Slovakia F2, Piešťany | Futures | Clay | Grégoire Jacq | 4–6, 6–3, 3–6 |
| Loss | 0–2 | Aug 2017 | Slovakia F3, Bratislava | Futures | Clay | Filip Horansky | 4–6, 4–6 |
| Loss | 0–3 | Oct 2017 | Czech Republic F7, Jablonec nad Nisou | Futures | Carpet | Patrik Rikl | 4–6, 2–6 |
| Win | 1–3 | Mar 2018 | Egypt F9, Sharm El Sheikh | Futures | Hard | Patrik Néma | 2–6, 6–3, 6–3 |
| Win | 2–3 | Mar 2019 | M15 Sharm El Sheikh, Egypt | World Tennis Tour | Hard | Jacopo Berrettini | 6–4, 6–4 |
| Win | 3–3 | Apr 2019 | M15 Sharm El Sheikh, Egypt | World Tennis Tour | Hard | Daniel Michalski | 6–2, 6–3 |
| Win | 4–3 | Apr 2019 | M15 Sharm El Sheikh, Egypt | World Tennis Tour | Hard | Jakub Paul | 6–4, 6–3 |
| Loss | 4–4 | Jun 2019 | M25 Pardubice, Czech Republic | World Tennis Tour | Clay | Manuel Guinard | 4–6, 7–5, 6–7$^{(6–8)}$ |
| Win | 5–4 | Jul 2019 | M15 Piešťany, Slovakia | World Tennis Tour | Clay | Fabian Marozsan | 6–1, 4–6, 6–1 |
| Win | 6–4 | Sep 2019 | M15 Bratislava, Slovakia | World Tennis Tour | Clay | Kirill Kivattsev | 7–6$^{(7–3)}$, 6–3 |
| Win | 7–4 | May 2022 | Troisdorf, Germany | Challenger | Clay | Zizou Bergs | 6–1, 6–4 |
| Win | 8–4 | Oct 2022 | Alicante, Spain | Challenger | Hard | Nick Hardt | 6–3, 6–4 |
| Loss | 8–5 | Oct 2022 | Ortisei, Italy | Challenger | Hard (i) | Borna Gojo | 6–7$^{(4–7)}$, 3–6 |
| Loss | 8–6 | Sep 2023 | Istanbul, Turkey | Challenger | Hard | Damir Džumhur | 6–7$^{(5–7)}$, 3–6 |
| Win | 9–6 | Oct 2023 | Ortisei, Italy | Challenger | Hard (i) | Maks Kaśnikowski | 6–7$^{(4–7)}$, 7–6$^{(7–4)}$, 7–6$^{(8–6)}$ |

### Doubles: 11 (5–6)

* Legend
* ATP Challenger (1–3)
* ITF Futures (4–3)
* Finals by surface
* Hard (3–2)
* Clay (1–3)
* Grass (0–0)
* Carpet (1–1)
| Result | W–L | Date | Tournament | Tier | Surface | Partner | Opponents | Score |
| Win | 1–0 | Feb 2016 | Turkey F6, Antalya | Futures | Hard | Alex Molčan | V. Alekseenko F. Ferreira Silva | 7–6$^{(9–7)}$, 7–6$^{(7–5)}$ |
| Win | 2–0 | Oct 2016 | Czech Republic F8, Jablonec nad Nisou | Futures | Carpet | Patrik Néma | Matej Vocel Pavel Motl | 6–1, 6–3 |
| Loss | 2–1 | Oct 2016 | Czech Republic F9, Opava | Futures | Carpet | Patrik Néma | P. Matuszewski Grzegorz Panfil | 1–6, 3–6 |
| Win | 3–1 | Apr 2017 | Greece F4, Heraklion | Futures | Hard | Patrik Néma | H. Callahan Nicholas S.Hu | 6–4, 6–2 |
| Loss | 3–2 | Jul 2017 | Slovakia F1, Trnava | Futures | Clay | Patrik Néma | P. Kekercheni D. Kalenichenko | 2–6, 7–5, [8–10] |
| Loss | 3–3 | Apr 2019 | M15 Sharm El Sheikh, Egypt | World Tennis Tour | Hard | Marek Jaloviec | Michal Dembek Daniel Michalski | 2–6, 6–3, [8–10] |
| Loss | 3–4 | Jun 2019 | Bratislava, Slovakia | Challenger | Clay | Alex Molčan | Joran Vliegen Sander Gillé | 2–6, 5–7 |
| Win | 4–4 | Sep 2020 | M15 Jablonec, Czech Republic | World Tennis Tour | Clay | Uladzimir Ignatik | Filip Duda Petr Nouza | 6–3, 7–6$^{(7–4)}$ |
| Loss | 4–5 | Nov 2020 | Bratislava, Slovakia | Challenger | Hard | Alex Molčan | Harri Heliövaara Emil Ruusuvuori | 4–6, 3–6 |
| Win | 5–5 | Feb 2021 | Cherbourg, France | Challenger | Hard | Alex Molčan | Albano Olivetti Antoine Hoang | 1–6, 7–5, [10–6] |
| Loss | 5–6 | Mar 2021 | Zadar, Croatia | Challenger | Clay | Alex Molčan | Blaž Kavčič Blaž Rola | 6–2, 3–6, [3–10] |

## Junior Grand Slam finals
### Doubles: 1 (1 runner-up)

| Result | Year | To | Surface | Partner | Opponent | Score |
| Runner-up | 2016 | Australian Open | Hard | Patrik Rikl | Alex de Minaur Blake Ellis | 6–3, 5–7, [10–12] |