Dan Evans lost in his first ATP Tour final, while fellow Briton Jamie Murray and partner Bruno Soares were beaten in the doubles in Sydney.
Evans, 26, led 4-2 in the first-set tie-break but eventually lost 7-6 (7-5) 6-2 against Luxembourg’s Gilles Muller.
However, he is already guaranteed to climb to a new career-high ranking just outside the top 50.
Murray and Brazilian Soares were beaten 6-3 7-5 by Dutch duo Wesley Koolhof and Matwe Middelkoop.
Elsewhere, American world number 23 Jack Sock won the Auckland Classic with a 6-3 5-7 6-3 victory over Portugal’s Joao Sousa.
Sock’s success comes after he was forced to retire because of illness in last year’s final against Spain’s Roberto Bautista Agut.
Belgian qualifier Elise Mertens beat Romanian third seed Monica Niculescu to win the Hobart International for her first WTA title.
The 21-year-old, ranked 127 in the world, lost nine of her first 10 points before taking control to beat world number 40 Niculescu 6-3 6-1.
The first Grand Slam of the year, the Australian Open in Melbourne, begins on Monday.