Russia's Daniil Medvedev showed Andy Murray just how much work he still has to do, when he beat the former world number one in straight sets in the Brisbane International on Wednesday.
Murray is making a comeback to the sport after a disastrous 2018, during which he played just six tournaments and was out of the game for 11 months with a hip injury.
He had a comfortable first round win over James Duckworth but found the step up in class too much against Medvedev, the 22-year-old Russian cruising to a 7-5, 6-2 win in just 80 minutes.
Medvedev is a rising star of the sport, winning seven titles in 2018 on his way to a world ranking of 16.
He broke Murray early in the first set and although Murray got back on level terms, Medvedev broke again late in the first set to gain the advantage.
Murray was broken twice at the start of the second to fall behind 0-4 and there was no way back for the 31-year-old Scot.
"In the second set I made a few too many mistakes, and obviously there was a period in the match from 5-5 where I lost six games in a row," Murray said.
"And I think when you obviously play better players, I mean he's 15 in the world or so, they will expose any errors that you make in your game or any shots that you're not hitting particularly well.
"And he did that tonight."
Medvedev will meet Canada's Milos Raonic in the quarter-finals.
The huge-serving Raonic fired down 21 aces in his 6-3, 7-6 (7/2) win over Serbian qualifier Miomir Kecmanovic to go with the 18 he served in the first round.
Earlier, Japanese star Kei Nishikori eased past American Denis Kudla 7-5, 6-2.
Dimitrov played some sublime tennis to down local favourite John Millman 6-3, 6-4.
Nishikori was joined in the quarter-finals by fellow countryman Yasutaka Uchiyama, who stunned British number one Kyle Edmund 7-6 (8/6), 6-4.
Chardy came back from losing the first set to beat Australian Nick Kyrgios 6-7 (5/7), 6-2, 6-3.
Top seeded Spaniard Rafael Nadal was a late withdrawal with a thigh strain.
He has been replaced in the draw by lucky loser Taro Daniel of Japan, who will play Jo-Wilfried Tsonga on Thursday.