Djokovic good enough to win while ill

L O ND O N » Novak Djokovic overcame an illness — and Alexander Zverev — to advance to the last four of the ATP Finals.

Using a tissue to blow his nose between points, Djokovic was able to beat Zverev 6-4, 6-1 on Wednesday for his second straight victory of the tournament.

“Unfortunately, today hasn’t been great in terms of that (illness),” Djokovic said. “Somehow I managed to gather the strength when I needed it.”

Djokovic’s passage to an eighth semifinal at the seasonending tournament was confirmed when Marin Cilic beat John Isner 6-7 (2), 6-3 6-4 in the late match.

The five-time champion saved two break points at 4-4 in the opening set and then broke Zverev in the following game to take the lead.

Zverev won only one more game.

“Maybe he was a little bit sick or something like that,” Zverev said. “But he still played like he felt at his absolute best. That’s kind of all that matters.”

Zverev’s earlier win over Cilic in the round-robin means both those players still have a chance of reaching the semifinals for the first time.

In the second set, Djokovic broke for a 3-1 lead and then lost just one more point as he remained on track to equal Roger Federer’s six titles at the tournament.

Victory in London would cap a remarkable season for Djokovic, who has already secured the year-end No. 1 ranking after dropping as low as No. 22 in June.