David Goffin rolled back the years to play his best match of the season to eliminate the number 1 seed, Carlos Alcaraz, from the Astana Open.
Goffin had squandered two match points in his qualifying match against Italian Luca Nardi but earned a spot in the main draw as a lucky loser. He played every bit as a former world number 7 and dominated the exchanges to seal the contest in one hour and 46 minutes.
Alcaraz failed to find any rhythm against Goffin, giving up his serve five times during his opening round loss at Astana Open. The two are tied at 1-1 in their head-to-head record.
Goffin will face Frenchman Adrian Mannarino in the next round of the ATP 500 event.
Alcaraz, meanwhile, has enjoyed a historic season himself by capturing ATP Masters 1000 crowns in Miami and Madrid before winning his first Grand Slam trophy at the US Open in a victory that propelled him to No. 1.
He is the youngest player to rise to the top in the history of the ATP Rankings.
Meanwhile, in other matches, Stefanos Tstisipas fared better than Alcaraz, winning his opening match 6-3, 6-4 against Mikhail Kukushkin.
Andrey Rublev, Hubert Hurkacz, and Roberto Bautista-Agut also won their opening round matches.