WATCH: Novak Djokovic completely melts down in Shanghai semifinal

It was a tough day at the office for Novak Djokovic on Saturday, and that’s putting it mildly.

The world No. 1, playing in his first tournament since the U.S. Open, recently said that regaining his desire to be on court and enjoying himself—not winning Grand Slams or retaining his No. 1 ranking—were his top priorities.

Well he sure didn’t seem to be having fun, nor was he at all relaxed, during his 6-4, 6-4 semifinal loss to Roberto Bautista Agut.

After hitting a backhand wide to drop the first set, the Serb ferociously smashed his racket against the ground three times.

Earlier in the set, in a harbinger of things to come, he angrily swung his racquet at the ground after sailing a forehand long.

In the second set he had words with chair umpire Carlos Bernardes, angrily asking him, “Are you seeing anything today?”

And reminiscent of his U.S. Open semifinal victory over Gael Monfils, Djokovic ripped off the top of his shirt in frustration after losing a critical point.

When the match concluded, the 29-year-old walked over to Bernardes to get a few more shots in.

''(Bernardes) was the star of the show,'' Djokovic said in his post-match press conference. ''That's what he wanted to be today.''

The actions were ugly, but the numbers might have been even uglier. Djokovic, one of the most consistent and efficient players in the history of the sport, made 29 unforced errors and converted just two of nine break-point opportunities.

Bautista Agut will play Andy Murray, who defeated Gilles Simon in straight sets, in the final.