Frances Tiafoe launched into an extraordinary expletive-laden rant at chair umpire Jimmy Pinoargote after his Shanghai Masters defeat to Roman Safiullin. 

Safiullin secured an upset victory over 13th seed Tiafoe in China, with the latter producing a flurry of expletives at umpire Pinoargote following his 5-7 7-5 7-6 (7-5) loss, having been given a time violation at 5-5 in the deciding tie-break.

The Ecuadorian official also took away a Tiafoe first serve due to time violations.

The 26-year-old American has enjoyed a positive season, making the US Open semi-finals and Cincinnati Open final, but is now likely to face a hefty punishment.

Meanwhile, Novak Djokovic produced a clinical display to beat Flavio Cobolli in the third round of the same tournament.

The four-time champion needed only 64 minutes to dispatch Italian Cobolli 6-1 6-2 and set up a fourth-round meeting with Safiullin.

Djokovic, playing his first ATP Tour event since the US Open, had looked a little rusty in his first match against Alex Michelsen but was sharp from the start this time and cruised through.

"From the beginning I had a clear game plan of what I need to do, staying aggressive and use every short ball to take the initiative in the point, and I've done that," said Djokovic.

Wet weather has badly affected the schedule in Shanghai and Cobolli had come through a two-and-a-half-hour tussle with Stan Wawrinka on Monday.

"Cobolli was evidently exhausted after last night's match. I think that has taken a toll physically on him today," added Djokovic.

There were also wins for Taylor Fritz, Stefanos Tsitsipas, Ben Shelton, Grigor Dimitrov and Holger Rune, while veteran Gael Monfils upset his French countryman Ugo Humbert 7-6 (9-7) 2-6 6-1.

Monfils, 38, will next face third seed Carlos Alcaraz, who he defeated in their last meeting in Cincinnati in August - not that he is expecting a repeat.

"I think he will beat me," said Monfils. "He will crush me 100 per cent.

"Last time I was very fortunate and it was not a good match from him and one of my good matches from me. His level is unbelievable. This kid is something else."

• Shanghai Masters - ATP 1000 (October 2-13)
• Wuhan Open - WTA 1000 (October 6-12)
• Almaty Open, Kazakhstan - ATP 250 (October 14-20)
• Stockholm Open, Sweden - ATP 250 (October 14-20)
• European Open, Antwerp - ATP 250 (October 14-20)
• Japan Open, Osaka - WTA 250 (October 14-20)
• Ningbo Open, China - WTA 500 (October 14-20)
• Erste Bank Open, Vienna - ATP 500 (October 21-27)
• Swiss Indoors, Basel - ATP 500 (October 21-27)
• Guangzhou Open, China - WTA 250 (October 21-27)
• Toray Pan Pacific Open Tennis, Tokyo - WTA 500 (October 21-27)

Sky Sports+ has officially launched and will be integrated into Sky TV, streaming service NOW and the Sky Sports app, giving Sky Sports customers access to over 50 per cent more live sport this year at no extra cost. Find out more here.