Tokyo, Japan, 2 October 2019 | AAP / tennis.com.au

John Millman fought back from a set down to win his first-round match at the Japan Open in Tokyo.

Qualifier Millman played the big points better to prevail 4-6 6-3 6-4 in two hours and eight minutes.

The world No.80 saved four of the five break points he faced and took advantage on two of his opportunities, one in each of the second and third sets, and closed out the match with his sixth ace.

Mannarino, the runner-up in Tokyo two years ago, was a finalist last week in Zhuhai – falling in straight sets to Alex de Minaur.

De Minaur twice came within a point of setting up a second-round clash with Millman, but later on Wednesday South Africa’s Lloyd Harris finally took down the Australian 6-3 6-7(6) 7-6(8) after more than three hours on court.

Millman is in the same quarter of the draw as countryman Jordan Thompson, who won through to the last 16 on Tuesday.

He will next play Harris, a player with whom he has split two career meetings, which both came on the ATP Challenger circuit in 2017.

De Minaur arrived in Japan fresh off that title in Zhuhai, yet looked slightly off in his clash with Harris, the world No.99.

Yet the young Aussie fought hard; in the second set he was down a minibreak and just two points from defeat before escaping to set the match to a third.

Here, he would rue his missed opportunities.

Leading 3-1 in the tiebreak, De Minaur two points later missed a makeable overhead and flung his racquet, earning a code violation for racquet abuse. This came with a point penalty because earlier he received a warning for swatting away a ball in frustration.

Now he trailed 3-4, although he did well to refocus and played solidly to earn two match points.

Harris, however, had his big first serve to bail him out of trouble, which it did on both of those match points.

He eventually outlasted the Australian in a gruelling point to win in three hours and two minutes, finishing the match with 18 aces.