Murray moves into Brisbane International semis
Murray next plays fifth-seeded Kei Nishikori of Japan, a 6-4, 7-6 (3) winner over 2012 Brisbane finalist Alexandr Dolgopolov.
Brisbane: Andy Murray was back on his game on Friday, with coach Ivan Lendl watching closely as he beat Denis Istomin 6-4, 7-6 (3) to reach the Brisbane International semi-finals.
The 25-year-old Murray next plays fifth-seeded Kei Nishikori of Japan, a 6-4, 7-6 (3) winner over 2012 Brisbane finalist Alexandr Dolgopolov.
Murray had lapses in his opening three-set win over No. 199-ranked qualifier John Millman the previous night, while Lendl was en route to Australia, but had no serious trouble in his second match of the year.
The first of Murray's three titles in a breakthrough 2012 season was in Brisbane, where he started working with former No. 1-ranked Lendl. The other titles were career-defining triumphs at the London Olympics and US Open.