Spanish number two Roberto Bautista Agut safely booked his place in the second round with an efficient win over Feliciano Lopez in straight sets.
Bautista Agut came out of the blocks fast quickly taking two breaks of serve at the first time of asking to wrap up the first set 6-2.
The second set was more of the same but not as clinical as the Bautista Agut, 31, converted two out of five set points to seal the set again 6-2.
Un primer paso importante. Complicado reanudar el juego un día después, además de hacerlo contra Feliciano López. ¡Vamos!
— Roberto BautistaAgut (@BautistaAgut) January 21, 2020
Important first step. It is not easy to play a match like this. Vamos!
#AusOpen #RobertoBautistaAgut #RobertoBautistaAgutAusOpen #Atp pic.twitter.com/BejH6Nu7PE
Lopez, 38, the singles and doubles champion at Queen's Club last year, improved in the third set but it was not enough as he went down 6-2, 6-2, 7-5.
Next up for the world number nine is a second-round clash against 22-year-old American wildcard Michael Mmoh, who comfortably saw off Spaniard Pablo Andujar in 6-1, 6-4, 6-4.
Meanwhile, 2014 champion Stan Wawrinka overcame the spirited Bosnian, Damir Dzumhur, in four sets winning 7-5, 6-7 (4-7), 6-4, 6-4.
Feisty Italian ace Fabio Fognini also went through as he stormed back from two sets down to beat a bad-tempered Reilly Opelka 3-6, 6-7 (3-7), 6-4, 6-3, 7-6 (10-5).
There were no such issues for fifth seed Dominic Thiem as the Austrian triumphed over Frenchman Adrian Mannarino winning 6-3, 7-5, 6-2.
Seventh seed Alexander Zverev got his Australian Open campaign off to the perfect start as he battled past Italy's Marco Cecchinato 6-4, 7-6 (7-4) 6-3.
First win of the new decade ✅@AlexZverev def. Marco Cecchinato 6-4 7-6(4) 6-3 to progress to the second round of the #AusOpen for the fourth straight year.#AO2020 pic.twitter.com/Yaq78fWMnl
— #AusOpen (@AustralianOpen) January 21, 2020
However, there was no good news for Canadian tennis fans as young prodigies Felix Auger-Aliassime and Denis Shapovalov fell at the first hurdle, losing to Latvian Ernests Gulbis and Hungary's Marton Fucsovics respectively.
At 4️⃣0️⃣ years of age, he's done it again!@ivokarlovic gets past Canada's Vasek Pospisil 7-6(4) 6-4 7-5 to advance to his 10th #AusOpen second round.#AO2020 pic.twitter.com/NXl3e2d4wX
— #AusOpen (@AustralianOpen) January 21, 2020
However, the oldest man in the draw lived to fight another day as 40-year-old big-serving Croatian Ivo Karlovic, "Dr. Ivo", eased past another Canadian, Vasek Pospisil, 7-6 (7-4), 6-4, 7-5 to book a second-round clash with 10th seed Gaël Monfils.