Alexander Zverev apologised in the face of heckles from the O2 Arena crowd for a controversial incident in his 7-5 7-6 (7-5) ATP Finals victory over Roger Federer.
Zverev became the first German since Boris Becker in 1996 to reach the final but drew the ire of sections of the auditorium when he stopped playing mid-point during the second-set tie-break.
A ballboy behind Federer dropped a ball which rolled towards the court, the eventually replayed point going the way of Zverev, who went on to see out the match.
Zverev, 21, was booed as he started his on-court interview by some who deemed him to have gained an unfair advantage and he immediately moved to apologise for the incident.
"First of all I want to apologise for the situation in the tie-break," he said. "The ballboy dropped the ball and it's in the rules that we have to replay the point."
Interviewer Annabel Croft also reminded the crowd of the rules and urged spectators to be "a little bit more respectful" to Zverev, who played superbly and will face Novak Djokovic or Kevin Anderson in the final.
Zverev continued: "I apologised to Roger at the net already and he said it's okay, that's obviously in the rules like that.
"I want to apologise to the crowd as well. I know there are a lot of Roger fans here. As he deserves, he should [have a lot of fans].
"For what he's achieved and the kind of guy he is, he should have the most fans in the world. And obviously here in London, especially, with how much history he has here.
"The crowd has been amazing and fair the whole match. I'm very sorry that this happened. I didn't mean to upset anybody. That's all I can say. Sorry."
Tournament director Adam Hogg later tweeted: "Astonishingly disappointing reaction from the crowd.
"Huge credit to Sascha Zverev for reaching his first final here at the ATP Finals. And well done Annabel Croft on handling the situation with aplomb."
Astonishingly disappointing reaction from the crowd.— Adam Hogg (@acphogg) November 17, 2018
Huge credit to Sascha Zverev for reaching his first final here at the #NittoATPFinals.
And well done @Annabel_Croft on handling the situation with aplomb.
|Athletics´ Chapman undergoes procedure on left shoulder|
|Marcelo: Real Madrid miss Ronaldo|
|Ronaldo right about Juventus team spirit – Allegri|
|Klopp: I´m not the pope of football tactics|
|Stade beat Ospreys on emotional Chauvin tribute night|
|Ligue 1 survival bid a marathon not a sprint for Monaco, as club appoints distance runner|
|Vertonghen eyeing Spurs future beyond 2020|
|De Bruyne injuries could be a blessing for City, says Guardiola|
|Emery prepared to face Arsenal´s centre-back crisis|
|Ulster complete Scarlets double, Exeter gain Gloucester revenge|
|Sheffield United 1 West Brom 2: Baggies comeback boosts automatic promotion push|
|Del Potro back on court following knee injury|
|Canelo v Fielding: Rocky ready to write his own fairytale in New York|
|Boca part company with Schelotto after Copa Libertadores loss to River|
|Canelo v Fielding: Tale of the tape|
|Juventus defender Cancelo has knee surgery|
|Canelo v Fielding: Alvarez and Rocky make weight in New York|
|Spalletti does not fear another mid-season crisis at Inter|
|Salah headlines CAF Player of the Year shortlist as Koulibaly misses out|
|Beckham Jr. out of Titans clash|
|Lipsky hits the front at Leopard Creek|
|Pederson coy over Wentz back injury|
|Liverpool ´not really likely´ to be active in January window, reveals Klopp|
|Always on the move and unpredictable - Pavard reveals surprising choice over toughest opponent|
|We need to get back to respect - Lampard alarmed by hate in football|
|Giles returns to England to replace Strauss as director|
|Hansen has no issue with Milner-Skudder Toulon switch|
|Juventus to rest Ronaldo after Torino showdown|
|Titmus strikes gold again as world records tumble in Hangzhou|
|Malinga to captain Sri Lanka in New Zealand|
|Rivaldo would like ´excellent´ Isco at Barcelona|
|United a long way from Mourinho´s vision|
|´Klopp denies an answer!´ - Liverpool boss dismisses questions about ´world-class´ Pogba|
|Returning Nowitzki ´so tired´ after making NBA history|
|Aguero and De Bruyne in contention for Manchester City v Everton|
|Simeone has no plans to cash in on Costa|
|Canelo v Fielding: Alvarez´s greatest nights|
|Fabregas: Chelsea being unfairly scapegoated over racism allegations|
|Crisis? What crisis? Klopp focuses on defensive solutions for United clash|
|Hope cannot inspire Windies as Bangladesh cruise to series win|
|Benitez picks up Premier League Manager of the Month award|
|Chavez, Marquez and Canelo - Mexico´s greatest multi-weight world champions|
|Bale set to miss Real Madrid v Rayo Vallecano|
|Robben out until January as Bayern look to avoid serious injury|
|Milan avoid UEFA ban in FFP punishments.|
|Mourinho compares Liverpool to ´an amazing house´ but insists trophies matter|
|Brisbane Roar 2 Melbourne Victory 4: Muscat´s men hit A-League summit|
|Bumrah confident second Test is ´in the balance´ after India recovery|
|Isco gesture was for a corner or foul, claims Solari|
|Harris leads Australia into ascendancy on day one|
|ATP announces candidates to host future Finals|
|Ronaldo: Juventus fans refuse to lose to Torino|
|Hero Rivers feared he had cost Chargers in KC|
|Williams would welcome Llorente back to Athletic Bilbao|
|Liverpool v Manchester United: Minding the gap|
|Milan elimination unjust, fumes Leonardo|
|Paul hails ´sick´ Harden after record-breaking display|
|Liverpool v Manchester United: Salah, Mane and Firmino v Rashford, Martial and Lukaku in Opta number|
|Canelo open to GGG trilogy as he chases place in Mexican history|
|The big Friday Premier League quiz|
|Harden posts record fourth 50-point triple-double in win over Lakers|
|Barcelona squad happy with Dembele, says Alba|
|Chargers rally past Chiefs to clinch playoff spot|
|WATCH: Chargers top Chiefs on dramatic two-point conversion in final seconds|
|Suns owner Sarver committed to keeping team in Phoenix|
|Chargers WR Allen leaves with injury after near-spectacular catch|
|Socceroos not giving up on Mooy for Asian Cup|
|Cooper says Raiders owner wanted to trade him to Cowboys|
|Pochettino jokes Levy is ´worried´ about losing him|
|Barcelona would welcome Morata – Alba|