Delray Beach, FL, USA, 18 February 2015 | AAP/AFP

Bernard Tomic and Thanasi Kokkinakis have won through to the second round of the Delray Beach ATP event in Florida, but a typically powerful serving display from fellow Australian Sam Groth wasn’t enough.

Tomic, who reached the quarterfinals of the Memphis Open last week, outclassed Tunisia’s Malek Jaziri 6-3 6-3 in his opening match on Tuesday.

Kokkinakis was too strong for Serbian Filip Krajinovic in a 6-2 6-3 victory at the hardcourt tournament.

The South Australian teen has now won four straight matches in Florida after coming through the qualifying rounds.

Groth slammed down 15 aces but went down 6-7(6) 7-6(5) 6-4 to Taiwan’s Yen-Hsun Lu.

Meanwhile, South African top seed Kevin Anderson and US second seed John Isner were each set to open in night matches against Australians – Anderson facing John-Patrick Smith and Isner meeting Marinko Matosevic.