Updated

World No. 1 and three-time champion Novak Djokovic secured a berth in the final, while Tomas Berdych upended defending and five-time overall champion Roger Federer in Friday's marquee semifinal action at the $1.785 Dubai Tennis Championships.

The red-hot Australian Open champion Djokovic extended his unbeaten streak to 17 matches by beating fourth-seeded former U.S. Open winner Juan Martin del Potro 6-3, 7-6 (7-4) in 1 hour, 44 minutes, while the third-seeded former Wimbledon runner-up Berdych saved three match points before knocking out the second-seeded former No. 1 Federer 3-6, 7-6 (10-8), 6-4 in 2 hours, 19 minutes on the hardcourts at Dubai Tennis Stadium.

Djokovic and last week's Marseille runner-up Berdych will determine the 2013 Dubai champion on Saturday. The Serb is a laughable 12-1 lifetime against his Czech counterpart, including a semifinal victory in Dubai two years ago. Djokovic has won their last 10 encounters.

The sensational Djokovic broke del Potro three times on Friday, while the tall Argentine settled for two breaks in a tight contest that saw the Serbian star overcome a 0-3 deficit in the second set.

Del Potro lost his focus after receiving a warning from the chair umpire for a time violation, while leading 3-1 in the second set.

"I lost my calm when I started to discuss with the umpire, and (Djokovic) come back in the second so quick," del Potro said. "He's the No. 1. When he feels the chance to improve his game, he always takes it. Tonight, he played better all the time."

Djokovic, who captured this Dubai event three straight years from 2009-11, is now 8-2 lifetime against del Potro, including wins in their last four meetings.

The 25-year-old Belgrade native will appear in his 45th career ATP final, seeking a 36th title. This marks his second final of 2013.

The 31-year-old Federer lost despite firing 13 aces, as he also committed an uncharacteristic five double faults against Berdych in the other tight affair on Day 5.

Berdych improved to 6-11 lifetime against Federer, including wins now in their last two meetings. The formidable 6-foot-5 Czech also topped the Swiss great in a U.S. Open quarterfinal back in September.

The reigning Wimbledon champ Federer was eyeing a trip into an eighth Dubai final. The Swiss icon beat U.S. Open titlist Andy Murray in last year's championship match in the UAE.

The 27-year-old Berdych will appear in his 18th career ATP final, seeking title number nine.

For the first time in the Dubai Tennis Championships' 21-year history the top- four seeds all reached the semifinals.

Saturday's winner will claim $429,600.