Watanuki beat Pankin 6-3, 7-5 at the Zhangjiagang event, powered by a sharp return display. He converted three of nine break points, saved five of six he faced and finished with 30 return points won to Pankin's 17.
Watanuki made the early move in the opener, breaking for 2-1 and again to close the set at 6-3. Pankin hit back in the second set with a break for 4-3, but Watanuki levelled at 5-5 and broke once more at 7-5 to seal the match.
The standout number was Watanuki's work on first-serve returns: he won 17 of 45 points against Pankin's first delivery and 83% of points behind his own first serve. Pankin landed a higher percentage of first serves, but Watanuki's pressure in return games proved decisive.