Roger Federer can go even further and break Jimmy Connors' record, according to former tennis legend Nicolas Kiefer.
Federer's victory at the Dubai Duty Free Championships on Saturdaybrought him the 100th tour level singles title of his career.
The 37-year-old is behind only Jimmy Connors in the Open era in men's tennis in terms of singles titles won and has the American's tally of 109 potentially in his sights.
Federer in numbers:
20Grand slam titles, an all-time record
8Wimbledon titles, an all-time record
5Federer has won both Wimbledon and the US Open on five consecutive occasions
6Australian Open titles, second only to Novak Djokovic
9Titles at the Gerry Weber Open in Halle and the Swiss Indoors in his home town of Basel
69Titles on hard courts
18Titles on grass
11Titles on clay
2Titles on carpet
6ATP Finals titles, an all-time record
12Titles won in 2006, Federer's most prolific season
24Consecutive finals won between October 2003 and November 2005
Federer had been stuck on 99 titles since triumphing at his hometown Basel tournament in October, but his victory over 20-year-old Greek Stefanos Tsitsipas means he is now nine titles away from tying Connors' incredible mark.
Kiefer, a former world No 4, is one of the very few men who have beaten Federer three consecutive times on the ATP Tour, and the German has backed his former foe to achieve even greater things in the future, despite his age.
"I'm sure he can go even further and make the new record because he is still playing great tennis and for what he has done for the sport, for the sponsors, for TV, for spectators, to see him playing for such a long time is great," said Kiefer, who retired with a 12-3 losing record to Federer.
Federer looks in shipshape condition after his triumph in Dubai
Men's top 10 singles title winners in the Open era:
Jimmy Connors 109
Roger Federer 100
Ivan Lendl 94
Rafael Nadal 80
John McEnroe 77
Rod Laver 74
Novak Djokovic 73
Bjorn Borg 64
Pete Sampras 64
Guillermo Vilas 62
Federer has won at least one ATP trophy in nearly every season since his first title, missing out only in 2016 when he suffered a knee injury.
The Swiss won 24 of his 100 titles in consecutive finals from October 2003 to October 2005 and the magnitude of Federer's achievement has not been lost on Kiefer, who is still amazed by his staggering feats.
"If he plays nine more tournaments, so there's a 10 per cent chance, laughed Kiefer. "Even at 37 he is winning tournaments, despite his age. He's still beating the young players.
Roger Federer has won 100 ATP titles in his career so far
"He may be getting older, but he is playing better and better. He doesn't need to play so many tournaments these days and I think he can still win tournaments despite counting on Indian Wells and Miami, and also on the grass with Halle and Wimbledon.
I would love to see him win one more Grand Slam tournament.
"He gets better with age. He gets stronger and stronger and better and better and on the big points he is one of the very best.
On the court you are by yourself, it's an individual sport and you have to find quick solutions at difficult moments.
The last three or four per cent is all in your mind and how you play the big points - he is the best at that, along with Novak Djokovic at the moment."
Kiefer finished his career with six ATP titles, including victory in Halle in 1999
Federer's eighth tournament success in Dubai has helped him climb back into the world top five ahead of the defence of his Indian Wells title, but Kiefer, an Olympic Games silver medallist in the men's doubles alongside Rainer Schuttler in 2004, says ranking points are the last thing on Federer's mind.
"Honestly, I think he doesn't care," he said. "He is happy when he is travelling, he is happy when he is playing tournaments, he is happy when he can compete against the best players and of course winning matches and tournaments and this is his goal."
Kiefer, who is now based in Hannover, is excited about the season ahead and feels Federer is more than capable of mixing it with the very best despite a number of young guns ready to steal the limelight from the established stars.
"It's going to be interesting to see how Federer gets on this season, but I think he can do well at the Masters 1000 events.
It also looks like he will play the French Open, but there's a big chance that he will win Wimbledon, although I think that all depends on Djokovic," said Kiefer. "The last few months Djokovic has been playing too solid.
"Federer now has time off so he will be ready for Indian Wells where I think he can go far.
But I also believe he is counting on the first few months of the year with Indian Wells, Miami, Madrid, then Roland Garros and the good thing is that he can choose his tournaments and prepare exactly for each tournament he is playing.
"It is not like the youngsters who have to play a lot of tournaments to get matches under their belts, so that also makes a big difference."