"I'm really happy with how I played, how I stuck with it mentally... I took my chances well today," Millman said.
"I've come close a few times of late but couldn't quite get through, so a really good result, especially considering it's my first tournament on clay in a long time."
The 28-year-old Millman set up a quarter-final against Germany's Yannick Maden who overcame compatriot Maximilian Marterer 6-1 6-3.
Fourth seed Denis Shapovalov also suffered an early exit as the 19-year-old Canadian was beaten 6-2 6-4 by Georgia's Nikoloz Basilashvili.
Eighth seed Andreas Seppi powered past Russia's Mikhail Youzhny 6-1 6-2 to reach the last eight.
(Reporting by Shrivathsa Sridhar in Bengaluru, editing by Ed Osmond)
Share
