If 2017 was the year Roger Federer and Rafael Nadal stunned the world with their triumphant comebacks from injury, 2018 has, until now, been all about the Swiss giant.
Federer has been enjoying his best ever start to a year as he became, at the age of 36, the oldest player to hold the ATP number one ranking. At the Australian Open he became the first man to win 20 Grand Slam titles, and with Nadal currently sidelined with a hip injury, the ATP 1000 events at Indian Wells and Miami represented a chance to stretch his lead at the top.
However this time the defending champion met his match as he lost a pulsating final 6-4 6-7 (8-10) 7-6 (7-2) to Juan Martin del Potro. Instead of a sixth Indian Wells title, Federer was left tasting defeat for the first time all year, while del Potro was able to celebrate winning his maiden Masters 1000 event.
The latter statistic may seem strange for a player who has a Grand Slam on his tennis CV, but for del Potro the years have often been unkind. He has been forced to have wrist surgery three times, taking large chunks of time out of his career and hampering his backhand. His best tennis since his 2009 US Open triumph has come in the Olympics, where he took silver in Rio against Andy Murray after securing the bronze medal in London.
However, the start del Potro has now made to this year means he has to be considered a strong contender when the Championships, Wimbledon come along, as well as for the other big tournaments.
Like Federer, he has won two tournaments this year and is clearly enjoying some of the best form of his career. There is nothing wrong with his temperament or confidence - he had to see off three Federer match points in the final set - and that big, booming forehand remains an immensely potent weapon. He admitted to shaking with nerves during the match, having missed match points of his own in the second set, but he was able to come through it all.
At the age of 29, the Argentinean is at a good age to challenge for the Grand Slams, being the same age Andy Murray and Novak Djokovic were when they won their most recent Grand Slam titles. Moreover, with Nadal's fitness uncertain, Novak Djokovic losing to world number 109 Taro Daniel on his comeback at Indian Wells, Stan Wawrinka still unfit and Andy Murray a couple of months away from playing again after surgery, now may be the ideal time for him to strike.
The tennis world has been in love with Roger Federer for many years and always will be, even when he finally hangs up his racket. But his is an era that has been special because of the quality of challenges he has faced. If Nadal, Djokovic, Murray and Wawrinka are not able to stop him for various reasons and Marin Cilic can do no more than lose finals, many will welcome further successes by one of the most popular players on the circuit.
Juan Martin del Potro may have lost much of his career to injury, but the very best of it may be just starting.
Image: Al Bello/Getty Images from Keith Prowse subscription