After heading off two break factors within the opening recreation, Ruud was the primary to interrupt after quite a few wayward photographs from his opponent.
Although Alcaraz continued to wrestle to seek out the courtroom, he had the chance to stage within the subsequent recreation however at break level noticed his forehand deflect out off the online wire.
Two additional possibilities adopted however Ruud withstood the hazard and was rewarded for his resolve when Alcaraz once more positioned a forehand out of bounds for the double break.
Ruud served out the set to like with an ace, solely the second set he had taken from Alcaraz – who hit 18 unforced errors and landed lower than 50% of his first serves within the opener.
However the Spaniard reset for the second set, dropping only a single level throughout his first three service video games earlier than breaking for the primary time.
He seemed to be cruising in the direction of levelling the match however Ruud fought again – incomes himself two break again factors with a lob on to the baseline, however needing just one as Alcaraz netted a backhand.
As Alcaraz’s stage continued to slide, a rejuvenated Ruud – who had been simply two factors from dropping the set – broke once more earlier than serving out the win with an ace on his third match level, capping a run of 5 straight video games.
Alcaraz and Ruud are joined within the John Newcombe Group by German Alexander Zverev – a two-time ATP Finals champion – and Russian Andrey Rublev, who play in Monday’s night session from 19:30 GMT.