Tennis history was created this week, and it all comes down to money.
Rafael Nadal moved to $10,700,000 (£6.7m) for the season this week, and it is the first time ever that two players have cracked the eight-figure barrier in the sport.
Who was the other? Well, it is not a rival player from the ATP Tour.
Serena Williams is the other legendary tennis star to have reached the eight-figure mark - a women's prize money record - meaning that one player from each tour has done so this year.
To date in her career, Serena has racked up an incredible $51,738,481 in prize money alone, while Rafa has $60,761,862.
At the ages of 32 and 27 respectively, and with years still ahead of them on the main tours, life is very good for this year's dominant forces.
It is, perhaps, no surprise then that it was Serena and Rafa who were the two players bemoaning the tax they had to pay on their earnings.
Only in September, after the pair won the respective titles at the US Open, did both complain that some of their $3.6 million top prizes were to be taken from them in taxes.
Not only did the duo net the $2.6m winner's cheques, but they also received $1m bonuses for having enjoyed the most successful run-ups in pre-US Open tournaments.
The US Tennis Association increased the prize money to record levels this year and the victory boosted 13-time Grand Slam champion Nadal's career total above $60 million, but it also meant that more money came out of the champion's pockets in taxes.
"At the end, it's a lot of money anyway, but that's not the real prize money,'' Nadal said. ''You have to pay the tax, and in Spain today it is 56 (per cent), I think.
''Anyway, a lot of money. Is more than half. Is more than half less and then is Euros.''
Williams, a 17-time Grand Slam winner and five-time US Open champion, faces a hefty bite from 'Uncle Sam', meanwhile.
''Someone told me today I passed 50 (million), but half of that goes to my Uncle Sam. I love him. I'm always giving him half my money," she said.
''I think my dad got me into tennis because of the money, but me being naive and silly, I never thought about it.''
The amount of money Rafa and Serena have to fork out on taxes may well be galling, but most people would recognise that they are both doing okay for themselves this year.