Reigning champion Andy Murray needed all three sets to win his second-round match at the season-opening Brisbane International tennis event, an Australian Open tune-up.

The top-seeded U.S. Open and Olympic titlist opened his 2013 season with a 6-1, 5-7, 6-3 victory over game Aussie qualifier John Millman on the hardcourts at Queensland Tennis Centre. The British star moved on in 2 hours, 5 minutes on Day 4.

Murray, who beat Ukrainian Alexandr Dolgopolov in last year's Brisbane finale, will encounter Uzbekistan's Denis Istomin in Friday's quarterfinals.

Meanwhile, capable Bulgarian Grigor Dimitrov ousted second-seeded Canadian slugger Milos Raonic 6-3, 6-4 and Istomin erased wild card and aging Aussie hero Lleyton Hewitt 7-5, 7-5. Dimitrov won all 26 of his first-serve points en route to his upset of Raonic.

The former world No. 1 and two-time major champion Hewitt captured this event in 1998 and 2000 and was the runner-up in 1999 when it was held in Adelaide.

One other second-round bout saw seventh-seeded Austrian left-hander Jurgen Melzer top rising Belgian David Goffin 6-4, 7-6 (7-4).

Friday's other quarters will pit third-seeded Frenchman Gilles Simon against former Aussie Open runner-up Marcos Baghdatis of Cyprus, a fourth-seeded Dolgopolov versus fifth-seeded Japanese Kei Nishikori, and Melzer against Dimitrov.