The tie was played in searing summer conditions in Sydney, Australia, with a severe heatwave warning in effect as temperatures topped 100 degrees Fahrenheit.
Bencic kicked off the matchup by defeating Mertens in the opening match, 6-3, 4-6, 7-6 (0), to give Switzerland an early lead.
Belgium responded when Zizou Bergs outlasted a dialed-in Stan Wawrinka, 6-3, 6-7 (4), 6-3, leveling the tie at 1-1. The three-time Grand Slam champion, 40, is playing his final season before retirement and remains eager to add to his trophy cabinet.
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“The team spirit is amazing and it starts with the captain,” Bencic said, referring to Wawrinka.
“He’s supporting all throughout my match and then he goes out to play his own match and then he’s back to support the doubles.
“It starts with him but then with all the energy from our bench it gives us such a spirit to win.”
