Stefanos Tsitsipas hurt his father in a mid-match meltdown during his clash with Australia's Nick Kyrgios at the ATP Cup.

Greek captain Apostolos Tsitsipas, who coaches the 21-year-old, was caught by Tsitsipas' angry racket swipe as he reacted to losing the opening set on a tie-break in Brisbane.

Tsitsipas Sr reacted with shock and moved to sit further away from his son, with a bruise visible on his arm.

Tsitsipas was given a warning by the umpire as well as a talking-to from his mother, Julia Apostoli.

The world number six then received a point penalty for hitting a ball in anger early in the second set and, although he levelled the match, it was Kyrgios, for once a picture of control down the other end, who eventually prevailed 7-6 (7) 6-7 (3) 7-6 (5).

The Australian fell on his back after a final backhand winner down the line as the home nation, who were already through to the quarter-finals, maintained their perfect record.