Novak Djokovic defeated Belgium's Zizou Bergs 6-3, 7-5 at the Rolex Shanghai Masters on Thursday to become the oldest-ever ATP Masters 1000 semifinalist at 38.
The fourth-seeded Serbian star reached his record-extending 80th Masters 1000 final four and is seeking his record-extending fifth title in Shanghai.
His unlikely opponent is qualifier Valentin Vacherot of Monaco, who rallied for a 2-6, 7-6 (4), 6-4 victory against No. 10 seed Holger Rune of Denmark in Thursday's other quarterfinal.
Djokovic enjoyed a more comfortable match against Bergs after struggling battling exhaustion and a leg injury in hot and humid conditions in his fourth-round win against Spain's Jaume Munar.
Djokovic, who improved to 27-0 this season when winning the first set, saved four of five break points and com