Mercedes Cup 2018: Prajnesh Gunneswaran beats World No. 23 Denis Shapovalov in first ever ATP World Tour appearance

Indian tennis star Prajnesh Gunneswaran beat World No. 23 Denis Shapovalov in the first round of the Mercedes Cup in Stuttgart on Wednesday in what was his first appearance in the main draw of any tournament on the ATP World Tour.

The 169th ranked Indian pulled off a huge upset as he beat the sixth-seeded Canadian 7-6 (6), 2-6, 6-3 in a match that lasted a little less than two hours.

Gunneswaran had qualified for the main draw when he beat World No. 207 Christian Harrison 6-3, 4-6, 6-3 in the final round of qualifying on Sunday. Against Shapovalov, though, the task was much tougher and few fancied a win for the Indian.

After all, Shapovalov, who is only 19, is considered as one of the biggest upcoming stars in world tennis. The youngster already boasts of a famous win against Rafael Nadal when he was just 18 and is seen as a future World No. 1.

However, on Sunday, at the ATP 250 tournament in Stuttgart which serves as a Wimbledon warm-up event, there was only one winner. Right in the very first game, Gunneswaran broke Shapovalov's service. But then, he dropped his serve and the set went to a tie-break. He went on to win four of the last five points to win 8-6.

In the second set, the left-handed Canadian star dominated, breaking Gunneswaran twice. Despite that, the Indian turned things around in the final set and broke Shapovalov twice to race to a 5-0 lead. Shapovalov managed to save four match points and break at 5-1. But there was no stopping Gunneswaran who held his serve to pocket the set, and the match.

He will now meet Guido Pella of Argentina in the round of 16, who went past John Millman 6-2, 6-2. A win against the World No. 75 will, in all probability, put him up against Roger Federer who is making a comeback to the court in this grass-court tournament after giving the clay season a miss.

Gunneswaran has been on a solid run of form over the last few months. Earlier in the year, he helped India secure a place in the Davis Cup World Group play-offs when he prevailed in the final rubber against China in April. The 28-year-old followed it up with his maiden ATP Challenger title win in Kunming.

At the French Open, he reached the final round of qualifying at the French Open last month before crashing out. He did get a chance to be in the main draw when Aussie star Nick Kyrgios withdrew, but, by then, he was already on a flight to Vicenza, Italy to play the main draw of a Challenger tournament.