Novak Djokovic got more than he bargained for in his first competitive match of 2020 before fending off Kevin Anderson 7-6 (5), 7-6 (6) late Saturday to secure Serbia's win over South Africa at the ATP Cup.

The No. 2-ranked Djokovic, winner of a record seven Australian Open titles, was able to feed off the large Serbian crowd at Pat Rafter Arena in Brisbane to ensure his country got the new, season-opening team event started with a victory in Group A.

But he also had to remonstrate with the crowd when things got tense in the first tiebreaker, when spectators called out during rallies on consecutive points and Djokovic yelled toward the stands before holding his finger to his lips to demand quiet. The chair umpire also intervened to ask the crowd to “show good sportsmanship.”

“That was the Serbian crowd that was a little bit too excited,” Djokovic said. "It was in the heat of the moment and I'm sorry if I offended anybody, but it happened a couple of points in a row — I really didn't need them interfering in the point.

“But I'm really thankful for their support. I thought the atmosphere was Davis Cup-like.”

Top-ranked Rafael Nadal had an easier time clinching Spain's win over Georgia, beating Nikoloz Basilashvili 6-3, 7-5 in Perth after Roberto Bautista Agut raced to a 6-0, 6-0 win over No. 678-ranked Aleksandre Metreveli.

But No. 4-ranked Dominic Thiem went down in an upset to Bornic Coric, who clinched Croatia's win over Austria with a 7-6 (4), 2-6, 6-3 win in Sydney. Marin Cilic won the opening singles 6-7 (4), 6-4, 6-4 over Denis Novak to give Croatia a 1-0 lead.

“I'm really disappointed but I think it was a typical first match of the year. I'm always a little bit struggling with the first match,” Thiem said. “I hope that it's going to be much better on Monday.”

The night-time matches in Groups A and B were both sealed before the doubles, but in starkly contrasting fashion.

Former No. 5-ranked Anderson was coming off an injury-plagued season, including surgery on his right knee last September, and couldn't initially keep up as Djokovic dropped just two points in the first three games and raced to a 4-1 lead.

But the 6-foot-8 South African warmed to the task and broke Djokovic's serve in the seventh game when he chased down a drop shot and produced a forehand winner. Then he saved five breakpoints in the eighth game to get back on serve, heightening tension in the crowd and sparking chants of “Nole, Nole, Nole, Nole” from the pro-Djokovic crowd, referring to his nickname.

The second set also went to a tiebreaker, with Anderson getting a chance to serve for the set at 6-5. But he netted a forehand, and Djokovic finished him off with a curling forehand winner to set up match point before hitting a winning volley.

“I started off extremely well, Kevin raised his game. His quality of tennis was high,” said Djokovic, who now leads Anderson 9-2 in career meetings, including the 2018 Wimbledon final. " I was pleased with the way I managed to weather the storm.”

Dusan Lajovic beat Lloyd Harris 3-6, 7-6 (4), 6-3 to give Serbia a 1-0 lead and the sweep was completed with a straight-sets win in the doubles.

In the earlier Group A match, Gael Monfils secured France's victory over Chile with a 6-3, 7-5 win over Cristian Garin 6-3, 7-5 after Benoite Paire's 6-7 (3), 6-3, 6-3 victory over Nicolas Jarry. Chile cut the final margin to 2-1 when Jarry and Garin combined to win the doubles.

Japan swept its opening Group B match with straight-sets wins in both singles and the doubles against Uruguay in Perth. Go Soeda beat Martin Cuevas 6-1, 6-3 and Yoshihito Nishioka had a 6-0, 6-1 win over Pablo Cuevas in the singles matches.

Argentina needed a win in the doubles to edge Poland 2-1 in their Group E match in Sydney. Guido Pella gave Argentina the lead with a 6-2, 2-6, 6-2 victory over Kamil Majchrzak before Hubert Hurkacz leveled with a 4-6, 6-2, 6-3 win over Diego Schwartzman.

Maximo Gonzalez and Andres Molteni beat Hurkacz and Lukasz Kubot 6-2, 6-4 to secure Argentina's triumph.

The 10-day, 24-team tournament will conclude with a final in Sydney on Jan. 12, leaving players time to fine-tune for the Australian Open in Melbourne.