Former world No.1 Andy Murray looked back to his best on grass as he beat Nick Kyrgios 7-6 (7-5), 6-2 to move into the final of the Stuttgart Open after the Australian lost his cool in the second set and said he was racially abused by a fan.

The final is the 70th of Murray’s career and his second of the year after a runner-up finish in Sydney in January. The 35-year-old will face second seed Matteo Berrettini, who is playing his first Tour-level final of the season.

After an entertaining opening set where there was nothing to separate the two players, Murray sealed it in the tiebreak, after which Kyrgios broke his racket and earned a point penalty as well as a game penalty in the second set.

The Australian, who was constantly complaining to the umpire, then refused to continue playing, sitting in his chair until the supervisor came out and convinced him to finish the match.

A frustrated Kyrgios later said that he had retaliated after hearing a racial slur.

“When is this going to stop? Dealing with racial slurs from the crowd?” he wrote on Instagram.

“I understand that my behaviour isn’t the best all the time - but ‘you little black sheep’, ‘shut up and play’ - little comments like this are not acceptable.

“When I retaliate to the crowd, I get penalised. This is messed up.”