One is a multi-millionaire icon whose name transcends sport. The other has earned £220 this year and had to be persuaded by his other half to keep playing professionally.
Seventeen-time Grand Slam champion Roger Federer and British number 23 Marcus Willis are from polar ends of the tennis world.
Today they will meet as equals, on Centre Court from about 16:30 BST, in the second round at Wimbledon. Tennis, eh?! What a sport...
The 34-year-old Swiss has won an all-time record 17 Grand Slam titles, reached 27 Grand Slam finals, 23 consecutive semi-finals and 36 consecutive quarter-finals. He is one of only eight men to complete the career Grand Slam.
Willis? Since turning professional, he has moved up and down the world rankings - reaching a high of 322 in the summer of 2014.
But the 25-year-old plummeted down to 479th at the turn of the year, eventually dropping to 785th by the start of last month.
His trophy cabinet does not contain any ATP titles, just a handful of lower-level Futures titles.
Money, money, money
Saying Federer has made a handsome living as a tennis player would be an understatement. Winning those Grand Slam titles and 88 ATP Tour triumphs has raked in the second-most career prize money ever.
Willis, who still lives at home with his parents in Berkshire, has made a more modest living. The Briton's earnings are more than 1,000 times less than Federer's.
Before Wimbledon, he had only earned £220 in prize money during 2016. Over the same period Federer has pocketed over £633,000.
Can Willis cope with playing on the big stage?
Willis had never even played at Wimbledon before Monday's shock win against world number 54 Ricardas Berankis.
Now he will be strolling out on to Centre Court in front of 15,000 people.
Game, set and stats
Willis is the lowest-ranked qualifier to reach the second round at a Grand Slam since number 923 Jared Palmer at the 1988 US Open.
He is the lowest-ranked player to make the second round at Wimbledon since number 861 Tommy Haas in 2015.
The last time a British wildcard into men's singles qualifying reached the second round of the main draw was number 661 Chris Eaton in 2008.