Carlos Alcaraz overcame illness to defeat Andrey Rublev at the ATP Finals in Turin.
The 21-year-old Spaniard won 6-3 7-6 (10-8) despite cutting short his practice session on Tuesday after struggling with a chest complaint.
Sporting a pink nasal strip to help his breathing, the third seed won four consecutive games to take the first set in 37 minutes with a double break of serve.
He claimed the second in an epic tie-break, hitting 33 winners overall in the match compared to 14 for the Russian.
"I surprised myself the way I played from the baseline.