In what was an entertaining day of tennis in Dubai, the top seeds remained relatively unscathed but there were a few close calls.
Wawrinka squeezes through against Stakhovsky
Stan Wawrinka came from a set and a break down to beat Sergiy Stakhovsky and book a place in the second round of the Dubai Duty Free Championships.
The French Open champ beat his Ukrainian opponent a week ago in Marseille, having to save two match points on that occasion, and this battle would prove to be just as difficult for the world no.4, who at one stage, lost six games in a row and was two points away from defeat, only to drag himself over the finishing line once again.
It wasn't at all pretty from Wawrinka, but he did get the job done. His next opponent will be Croatian qualifier Franko Skugor, who at 6ft 8in tall, could provide more problems for Stan the Man if he is again not at his best.
Skugor beat British duo James Ward and Kyle Edmund in qualifying, and backed those wins up by defeating Russia's Teymuraz Gabashvili with the loss of just five games and incredibly for the Croat, this is his first win in an ATP main draw for six years.
Kyrgios overcomes Klizan as Berdych breezes through
In the battle between the Rotterdam and Marseille champs, it would be the latter who came out on top, as Nick Kyrgios, off the back of his first ATP title in the south of France on Sunday, overcame seventh seed Martin Klizan.
The Aussie didn't drop a set, let alone his serve, on route to tournament triumph last week, but it wasn't so easy here, as he had to come from a set down to prevail against his Slovakian opponent. Mikhail Kukushkin of Kazakhstan will be next for the 20-year old, after a 7-5, 7-6 win versus Denis Istomin.
Finalist in both 2013 and 2014 in Dubai, third seed Tomas Berdych is hoping for another fine run, and has begun strongly, with a 6-1, 6-4 win over Portugal's Joao Sousa; the Czech's victory extending his opponent's losing streak to five.
Italian qualifier Thomas Fabbiano will be Berdych's second round opponent, after his surprise straight sets success over Leonardo Mayer.
Bautista Agut victorious, Kohlschreiber and Coric also progress
Roberto Bautista Agut, seeded fourth here, has been hugely impressive in the opening couple of months of 2016, with titles in Auckland and Sofia. His quest to add a third crown to his trophy cabinet got off to a winning start, as he defeated Italy's Simone Bolleli 6-2, 6-4.
The Spaniard dropped just ten points on serve in a solid, all-round display to notch up his 15th victory of the year, to set-up a last-16 encounter with the talented South Korean youngster Hyeon Chung.
Elsewhere, eighth seed Philipp Kohlschreiber easily dispatched Turkey's Marsel Ilkan 6-1, 7-5, to set up an intriguing encounter with Croatian prospect Borna Coric, who reached the semi-finals of this tournament twelve months ago.
The 19-year-old beat Andy Murray on route to the last-four and will be hoping for a similar, if not, better result here; a 6-4, 6-4 win over Jiri Vesely the perfect start.
Lukas Rosol is also through coming from a set down to defeat Indian wildcard Yuki Bhambri; sixth seed Feliciano Lopez awaits in Round 2.