Teenager recovered from a heavy first set loss to defeat the veteran Czech, while there were also first round wins for Sharapova and Kasatkina
Shapovalov the new Canadian No 1 after edging Berdych in Italian Open thriller
Canadian teenager Denis Shapovalov proved why he is one of the most exciting talents in men's tennis after a thrilling 1-6, 6-3, 7-6 victory over the Czech Republic's Tomas Berdych in the first round of the Italian Open on Tuesday.
Shapovalov, who this week climbed 14 places in the ATP world rankings to No 29 following a march to the semi-finals in Madrid, quickly found himself trailing 0-5 to former world No 4 Berdych after an error-strewn start to the match.
After losing the first set, Shapovalov soon found his range in the second set, getting the better of Berdych in the baseline exchanges and finding consistency with his serve.
The 19-year-old Canadian claimed the all-important break in the fourth game, and after both players twice held serve, Shapovalov levelled the match at the third time of asking.
Neither player gave much away on their service games during the deciding set, leading to the inevitable tie-break.
Shapovalov then raced into a commanding lead, first at 4-0 then at 5-2, seemingly cruising to victory. However, Berdych clawed his way back into the contest, levelling at 5-5, only for Shapovalov to edge ahead and claim victory on his first match point.
The win not only sent Shapovalov into the second round, but ensures he becomes the new Canadian No 1, unseating long-term occupant Milos Raonic.
Earlier in the day, Damir Dzumhur, from Bosnia and Herzegovina, booked a second round meeting with world No 2 and undisputed king of clay Rafael Nadal after thrashing Spaniard Fernando Verdasco 6-3, 6-1 in just over an hour.
France's world No 16 Lucas Pouille had to grind through his first round match against local favourite Andreas Seppi to set up a second round clash with Britain's Kyle Edmund. Pouille, who reached the Dubai Duty Free Tennis Championships final earlier this year, came through 6-2, 3-6, 7-6.
Argentina's Diego Schwartzman enjoyed a much more straightforward outing, defeating Chilean Nicolas Jarry 6-4, 6-1, and will take on Frenchman Benoit Paire for a place in the third round.
In the women's draw, Maria Sharapova got her bid for a fourth Italian Open title underway with a 7-5, 3-6, 6-2 win over Australian Ashleigh Barty.
Russia's Sharapova, champion in Rome in 2011, 2012 and 2015, needed more than two-and-a-half hours to book her place in the second round where she will face Slovakia's Dominika Cibulkova.
Dubai finalist Daria Kasatkina made easy progress to the second round with a 6-0, 6-4 win over Australia's Ajla Tomljanovic and will next face American Danielle Collins.
Germany's former world No 1 Angelique Kerber is also safely through to the next round and will take on Romania's Irina Begu.
The pick of today's matches in the Italian capital includes an afternoon showdown between world No 4 Grigor Dimitrov and Japan's top-ranked player Kei Nishikori, as well as Argentina's world No 6 Juan Martin del Potro up against Barcelona finalist Stefanos Tsitsipas from Greece.
Defending champion Alexander Zverev, fresh from winning the Madrid Open title, also begins his campaign against Italian Matteo Berrettini.