First it was Jordan Thompson, now it’s the turn of Alexei Popyrin in Tokyo.

One day after Thompson eliminated world No.2 Alexander Zverev to throw the Japan Open wide open, Popyrin proved to be another giantkiller when he sent the seventh-ranked Karen Khachanov packing.

Popyrin defeated the Russian 6-4 6-2 on Tuesday to reach the last 16 of the ATP tournament.

It was a commanding performance from the 24-year-old Sydneysider, who dished out 11 aces to Khachanov’s seven, and won 90 per cent of his first serves.

He converted four out of 10 break-point opportunities while only losing serve once.

Tweet from @TennisAustralia

Popyrin will now meet Chilean Christian Garin, who overcame Sho Shimabukuro 6-4 3-6 6-3, for a berth in the quarter-finals.

And joining compatriots Thompson and Popyrin in the round of 16 is Alex de Minaur.

But Australia’s top-ranked player didn’t have things his own way against a spirited Jack Draper, as the pair battled for three hours and five minutes.

The tournament No.4 seed dropped the first 6-4, but then topped the Briton with two gritty efforts in tiebreakers winning 7-4 and 7-1.

De Minaur now takes on Argentinian Diego Schwartzman, who beat countryman Francisco Cerundolo 6-4 6-1, for a place in the last eight.

Thompson will now meet in-form American left-hander Ben Shelton,  who trumped local qualifier Taro Daniel 3-6 6-4 7-6 (7-2), in the next round.

Top-seeded American Taylor Fritz emerged unscathed in his encounter with Cameron Norrie, severing 13 aces on his way to beating him 6-3 6-3.

The 25-year-old American will next play Japanese wildcard Shintaro Mochizuki, who beat Tomas Martin Etcheverry in straight sets.

Casper Ruud, the No.2 seed, defeated another Japanese wildcard, Yosuke Watanuki, 7-6 (10-8) 6-3. Rudd next faces American player Marcus Giron.

-AAP