Defending champion Novak Djokovic reached his 17th successive Italian Open quarter-final with a tense victory over British number one Cameron Norrie.

The mood in a tetchy encounter worsened in the second set when Norrie smashed an overhead into the ankle of Djokovic, who had already given up the point.

Djokovic faces seventh seed Holger Rune or qualifier Alexei Popyrin next.

The Serb’s preparation for the French Open has been disrupted by injury but he is finding form in time for his bid for a 23rd Grand Slam singles title when it starts on 28 May.

Having delayed the start of the match for a few minutes while he was in the treatment room, Djokovic then wasted no time in racing into a 3-0 lead – and was not even held up by an early collision with the clock at the side of the court.

While Norrie slowed down Djokovic’s charge with a couple of holds and saved three set points – one with a rocketing backhand service return – he could do nothing about the fourth as Djokovic wrapped up the first set.

The Briton went a break down early in the second and then immediately broke back – but in controversial fashion.

Djokovic had already surrendered the point when he hit high to leave Norrie with an open court to put the ball into and was walking away with his back turned when Norrie fired his smash into Djokovic’s left ankle.

Norrie uttered a brief “sorry” and raised his hand in apology, earning whistles from the crowd and a huge glare from a clearly riled Djokovic.

With conditions cool and the mood on court even frostier, Djokovic went on to break to love for 5-4.

Having been made to wait at the start of the match, it was then Norrie’s turn to keep Djokovic waiting as he received treatment on court on his hip while the Serb prepared to serve for the match.

Djokovic did not let the delay disrupt his flow as he sealed victory on his second match point to stay on course for a seventh Italian Open title, with the pair exchanging a tense handshake and no words at the net.

More to follow.