Germany's Alexander Zverev saved two match points against Hubert Hurkacz to prevail 6-7(3) 7-6(6) 6-4 and level their United Cup mixed team tournament final against Poland at 1-1 on Sunday after Iga Swiatek outclassed Angelique Kerber 6-3 6-0.
Hurkacz was pushed hard by Zverev in a physically demanding opening set of his contest but the big-hitting world number nine edged the tie-break to give Poland hope of sealing a swift win for their first team title.
But Zverev saved two match points, including one with a sublime forehand pass to the back of the court at 6-4 down in the second set tie-break, before dragging himself back into the contest as Hurkacz struggled to stem the flow of errors.
The gutsy German moved ahead 4-3 with a break in the decider despite looking drained at times but kept up the pressure to win an epic encounter lasting nearly three hours on his second match point to force a mixed doubles decider.
World number one Swiatek earlier stepped up preparations for the Australian Open starting next Sunday by fending off Kerber after a high-quality start by both players.
The four-times Grand Slam champion moved up a gear in the opening set as Kerber, who returned to action in the tournament after 18 months on maternity leave, dropped her level having gone toe to toe with her opponent until 3-3.
The 22-year-old Swiatek looked unstoppable in the second set and she wrapped up the win in 70 minutes.