SHANGHAI (AFP) - Tennis' world No. 1 Novak Djokovic went crashing out of the Shanghai Masters semi-finals after his first-ever defeat by Spain's Roberto Bautista Agut on Saturday.

The 12-time Grand Slam winner and defending champion was broken four times as he lost 4-6, 4-6 to continue his poor run since winning his first French Open title in June.

The Serb suffered shock early defeats at Wimbledon and the Rio Olympics and was given a big scare by qualifier Mischa Zverev here in the quarter-finals before winning 3-6, 7-6 (7-4), 6-3.

"I'm so happy," said 15th seed Bautista, after beating Djokovic at the sixth attempt to reach his first Masters final.

"I'm just so happy how I've played this week.

"I'm feeling really good on this court and I hope to enjoy it until the last point here."

Andy Murray, the world No. 2, and Frenchman Gilles Simon play later to decide who will meet the 19th-ranked Spaniard in Sunday's final.