Germany won their opening Hopman Cup clash with Belgium in the doubles after Angelique Kerber and David Goffin took one singles win apiece.
Kerber needed tie-breaks in both sets as she edged Elise Mertens 7-6 (8-6) 7-6 (7-1) to put Germany on the front foot in Perth.
However, Belgium hit back in the Group A clash through David Goffin, who was a comfortable 6-3 6-3 victor over Alexander Zverev.
Goffin fired 12 winners to claim the opening set before battling back from 2-0 down in the second to tee up the deciding doubles.
Kerber and Zverev made the ideal start to the shortened first-to-four Fast4 format, breaking serve at the first attempt to seize the initiative.
That break was enough to settle the opening set and the German pairing edged a tie-break in the second to come away with a 4-2 4-3 (5-2) triumph.
Monday's action marked a return to competitive tennis for former world number one Kerber, who appointed Wim Fissette as her new coach in November after a woeful 2017 season.
"I think it was a good match from both of us; a really high quality," she said of her singles triumph. "For me, it gives me a bit of confidence starting the year like this, playing good tennis again.
"After the long break, playing tennis again, it is always different and tough but actually I am really happy about the first match and how I was feeling on court."