Defending champion Grigor Dimitrov survived two match points to end the hopes of local boy John Millman and reach the quarter-finals of the Brisbane International.
Brisbane native Millman had one chance on serve in a second-set tie-break and another crack on Dimitrov's, but both opportunities went begging in a dramatic contest.
And those misses were punished as the ATP Finals champion overcame a major scare against a player ranked 125 places below him to record a 4-6 7-6 (10-8) 6-3 victory.
World number three Dimitrov, making his season debut, had broken in the second set only to hand that straight back, and the Bulgarian won an epic rally to save a first match point before a mammoth forehand staved off the second.
Deflated by losing the set, Millman was outclassed in the decider, as Dimitrov earned a last-eight tie with Kyle Edmund following the Briton's 7-6 (7-3) 5-7 6-4 beating of Chung Hyeon.
Denis Istomin defeated Jared Donaldson 7-6 (7-5) 6-2 and will now meet Ryan Harrison, after the American recovered from going a set down to defeat Yannick Hanfmann.
Marin Cilic continued his march at the Maharashtra Open. The top seed was in impeccable form to beat Pierre-Hugues Herbert 6-3 6-2 in just over an hour to reach the semi-finals.
Gilles Simon awaits after the Frenchman beat qualifier Ricardo Ojeda Lara 6-2 6-3, while on the other side of the draw second seed Kevin Anderson recovered from going a set down to beat Mikhail Kukushkin 6-7 (3-7) 6-4 6-2, and will face Benoit Paire for a place in the final following his three-sets win over Robin Haase.
