Sumit Nagal had to be content with a runner-up finish at the ATP Tulln Challenger event after losing the singles title clash in straight sets to Czech Republic's Vit Kopriva, in Tulln on Sunday.
Teenage sensation Carlos Alcaraz steamrolled past Argentine lucky loser Juan Ignacio Londero 6-4, 6-2, 6-0 to kick off his French Open campaign in solid
Defending champion Andy Murray and ATP finals hopefuls Mikhail Youzhny and Fernando Verdasco all made surprise early exits from the Valencia Open on Wednesday. World number four and top seed Murray fell 6-2, 3-6, 6-2 to Argentine Juan Monaco in the second round, while world number 10 Youzhny pulled out at the start of the day with a back problem.
Rafael Nadal claimed a record-extending 10th Monte Carlo Masters title as he geared up for his beloved French Open with a 6-1, 6-3 victory against fellow Spaniard Albert Ramos on Sunday.
Australian Nick Kyrgios was involved in a fresh dispute after being accused of swearing at the BNP Paribas Open in California.
The Spaniard, who turns 36 next week, will next meet Dutch 26th seed Botic van de Zandschulp with a potential quarter-final looming against world number one Novak Djokovic who defeated him in last year's semi-finals.
Andy Murray has dismissed suggestions that the pressure of being the world's top tennis player is affecting his performance after losing to Spaniard Albert Ramos-Vinolas in the Round of 16 of the Monte Carlo Masters.
World number two Roger Federer launches his bid for a sixth US Open title, and his first since 2008, with a first-round match against Argentina's Leonardo Mayer at the Arthur Ashe Stadium on Tuesday.
Top seed Rafa Nadal, who has won the tournament 10 times, also reached the last eight after dispatching compatriot Guillermo Garcia-Lopez 6-1, 6-3 and claiming a record-extending 40th consecutive set on clay.
Top seed Nadal extended his winning streak to 13 matches with a 6-2, 6-1 demolition of American Jared Donaldson in the Qi Zhong Stadium before World No 2 Federer, to the delight of his sizeable Chinese fan club, got the better of Argentina's Diego Schwartzman 7-6(4), 6-4.
Rafael Nadal stayed on course for a record-extending 10th Monte Carlo Masters title when the Spaniard beat David Goffin 6-3, 6-1 in the semi-finals after the Belgian was denied a key point in controversial fashion on Saturday.
Murray, who suffered an elbow injury in March and made his return from a five-week layoff on Wednesday after a first-round bye, won the opening set in 48 minutes before losing concentration.
It will be the earliest meeting between the two since their first professional match in the second round of the 1998 Australian Open.
World No 1 Novak Djokovic and fourth-seeded Andy Murray each had to contend with different degrees of adversity before they advanced.
IMAGES from Day 1 of the Wimbledon Championships played on Monday.
Defending champion Sloane Stephens was sent packing from the Miami Open on Sunday after a 6-3, 6-2 loss to Germany's Tatjana Maria in the third round.
Venus Williams staged a spirited comeback to down third seed Petra Kvitova 4-6, 7-5, 6-4 and reach the third round of the BNP Paribas Open in Indian Wells on Saturday.
With the French Open starting on Sunday, Murray has accrued 1,210 to the 4,915 of Rafael Nadal and looks a pale imitation of the player who won his last 24 matches of 2016 to knock Novak Djokovic off his pedestal and seize power in men's tennis.
The seventh-seeded Bulgarian advanced to his eighth ATP World Tour Masters 1000 quarter-final with a 6-3, 7-5 victory over Del Potro, who struggled with the intense heat in the closing stages of the one hour, 39 minute match.
Garbine Muguruza reached the French Open quarter-finals for the third year in a row when a solid display earned her a 6-3, 6-4 victory against former champion Svetlana Kuznetsova.
Home sensation and wild card entrant Yuki Bhambri sprung a surprise by upsetting higher-rated Pablo Carreno Busta of Spain to enter the second round even as compatriot Somdev Devvarman made a shocking first round exit at the ATP Chennai Open.
Images from Day 1 of the US Open in New York, on Monday.
World number one Simona Halep saved three match-points before edging past an inspired Lauren Davis 4-6, 6-4, 15-13 in a thrilling marathon to reach the fourth round of the Australian Open on Saturday.