The fifth seed was utterly dominant as he brushed past his opponent in what proved to be a first-round win of consummate ease.
Tomic, the world number 28, took the opening set with a couple of impressive breaks of serve as he pinned Lacko back behind the baseline.
The second set was no easier for the world number 63 as the Slovak failed to make a real impression with an early break of serve leaving him under the cosh.
Tomic won through with a composed finish, and the Australian will next take on Kazakhstan's Mikhail Kukushkin after he beat Sam Querrey of the USA 6-2 7-5.
Seventh seed Denis Istomin battled through in three sets after a stutter in his match with Colombian Alejandro Falla, taking it 7-6(3) 1-6 6-1.
The world number 42 justified his seeding as he took the tie-break 7-3 in convincing fashion after being tested in the opening set.
But Falla responded in style with a crushing display of power-hitting in the second set, taking it 6-1 and leaving his opponent utterly stunned.
Istomin was not to be denied, however, and he replied with a reversed scoreline in the third and final set.
The Uzbek will next take on Nikolay Davydenko in the second round after the Russian beat Matthew Ebden of Australia in straight sets, 6-3 6-3.
Eighth seed Fabio Fognini was not as successful as he was defeated 7-6(3) 7-5 in his first-round encounter with Belgian Steve Darcis.
Fognini faltered badly in the opening set tie-break as the world number 61 Darcis stamped his authority on the match.
The Italian remained in contention at 5-5 in the second set, but Darcis again came through in clinical fashion to take it with a solitary break of serve.
Darcis will next face Filippo Volandri of Italy after he beat Belgium's Olivier Rochus 4-6 7-6 6-2.
In other first-round matches, Brazil's Thomaz Bellucci beat Donald Young of the US) 6-7(5) 6-0 6-3, while American Brian Baker surprised Ukrainian Sergiy Stakhovsky 6-7(2) 6-4 7-5.
Bellucci next faces Juan Carlos Ferrero, who beat Robin Haase 4-6 7-6 7-6, while Baker is handed a showpiece clash against France's Gael Monfils, who was given a bye to the second round.
Top seed John Isner of the United States was also spared a first-round match. He faces Xavier Malisse of Belgium next after he beat Yen-Hsun Lu of Taiwan 7-5 6-4.
Edouard Roger-Vasselin beat fellow Frenchman Benoit Paire 6-4 7-6(2) to set up a tie with Nicolas Almagro, also with a bye, while Grigor Dimitrov of Bulgaria beat Dudi Sela of Israel 7-5 6-1.
Dimtrov is rewarded with a second-round match against Gilles Simon.