Aslan Karatsev saw his phone light up with more than 200 text messages on Tuesday after he reached the Australian Open semi-finals.

“It’s amazing that I reached the semi-finals from qualifying,” said the World No. 114. “I’m just trying to enjoy the moment and not think about winning too much. [Just] playing round to round… I try to believe every match [in] what I’m doing on the court, and it’s helped me to win matches.”

Karatsev became the first man in the Open Era (since 1968) to reach the semi-finals on his Grand Slam debut after the Russian qualifier beat No. 18 seed Dimitrov 2-6, 6-4, 6-1, 6-2 on Rod Laver Arena on Tuesday.

The 27-year-old Karatsev believes that working with Yahor Yatsyk in Minsk, in addition to building the right team, has played a major part in his major breakthrough at Melbourne Park.

“In the end, I found a coach, Yahor Yatsyk, and this is the right guy for me,” said Karatsev. “He’s helped me a lot, [the] mental part, and then of course there is the technical stuff, as well. I like to work with him. We work a lot [on]… the mental part, to believe more in myself and to believe [in the game that I play. I was really lucky to find him, and we just met at one tournament. I played [at an ITF] Futures.”

It’s a remarkable run for Karatsev, who has played just 17 tour-level matches and moved from Russia to Halle, then to Barcelona and now Minsk in his quest to make it to the upper echelons of professional tennis.

It could have been very different for the talk of the tennis world. Five years ago, Karatsev struggled to overcome a long-term knee injury.

“There was a time when I was injured that was a difficult time for me, because I recovered after a [knee] injury, and started 2017 playing again,” said Karatsev. “[But] I felt the knee, and I said, ‘Whoa!’ I quit again for two-and-a-half months, almost three, and I think that was the most difficult part.”

Karatsev has been in great form since tennis resumed in August 2020 following a five-month suspension due to the COVID-19 pandemic, winning 18 of his final 20 ATP Challenger Tour matches in 2020 and claiming two trophies at that level.

Earlier this month, Daniil Medvedev described Karatsev as Russia’s “secret weapon” in their ATP Cup title-winning run in Melbourne. Karatsev has since beaten Gianluca Mager, Egor Gerasimov, eighth seed Diego Schwartzman, No. 20 seed Felix Auger-Aliassime and No. 18 seed Dimitrov en route to the Australian Open semi-finals.

Having started the 2021 Australian Open at No. 114 in the FedEx ATP Rankings, Karatsev is now set to break into the Top 50 on Monday.