Former world No.1 Novak Djokovic has bounced back from his French Open disappointment with a straight-sets demolition of Queenslander John Millman to open his account at London's Queen's Club.
Djokovic, who lost to Italian giant-killer Marco Cecchinato in the quarter-finals at Roland Garros earlier this month, was rampant in a 6-2 6-1 win.
Millman raced to a 40-0 lead in his opening service game but that was as good as it got for the 29-year-old. Djokovic got the first service break in the fifth game to go 3-2 ahead before taking another two games later.
The second set progressed in much the same fashion, Djokovic going up a break with the opening game before a marathon fifth game also went the way of the Serb, giving him a 4-1 lead.
"It was a good match," Djokovic said. "I can't really talk about too many negatives.
"The focus was there, right intensity every shot. Every shot was working beautifully."
The 12-time major champion credited a week hiking "with no kids" for his return to form.
"It was hiking with my wife for five days, if you really want to know," he said.
"It was a wonderful time after two years with not having a break without kids. We were far away from any tennis court, and it was the best way to clear the mind and also just have a possibility to slow down."
Djokovic will next face Grigor Dimitrov, who survived a tough first-round workout against Bosnia's Damir Dzumhur.
The 27-year-old Bulgarian was edged out in a second-set tiebreak but eventually prevailed 6-3 6-7 (7-4) 6-3, sealing victory with an ace.
There were also first-up wins for Jeremy Chardy, Julien Benneteau and Argentina's Leonardo Mayer, who upset South African third seed Kevin Anderson.