Turin, Nov 14 : In his ATP Finals debut, Carlos Alcaraz faced a formidable challenge from two-time champion Alexander Zverev of Germany, who delivered a clean-hitting performance to triumph 6-7(3), 6-3, 6-4 against the Spaniard. Zverev is making his sixth appearance at the prestigious year-end event, having won the title in his previous outing in Turin in 2021 and in London in 2018. The German used his experience to good effect against Alcaraz, staying composed on serve and from the baseline to move to 1-0 in Red Group play on Monday, reports ATP. After squandering a break advantage in the first set, the World No. 7 stayed positive, with his depth and consistency in the second and third sets causing a misfiring Alcaraz problems. The 27-year-old Zverev won 79 per cent (59/75) of his first-serve points and recovered from falling heavily on his left ankle in the third set to improve to 4-3 in the pair's ATP Head-to-Head series after two hours and 32 minutes. Zverev missed last year's event due to a right ankle injury he sustained during his 2022 Roland Garros semi-final against Rafael Nadal. He walked gingerly between points in the latter stages of his clash with Alcaraz after falling on his left ankle on Monday, but continued to improve to 13-8 at the Nitto ATP Finals. Alcaraz is chasing his seventh title of the season and first since he clinched his second major trophy at Wimbledon in July. The 20-year-old, who missed last year's event due to injury, is the youngest player in the eight-man field and is trying to become the youngest champion at the ATP Finals since Pete Sampras in 1991. Due to the round-robin format, he is still alive in Turin. /IANS