Nadal was able to assert his quality on the match quickly and was rarely troubled by his opponent in a professional display. Next up for the Spaniard will be a meeting with his compatriot Pablo Carreno Busta.
Earlier in the day, there was a routine win for fourth seed Daniil Medvedev, as he came through in straight sets against Pedro Martinez. Dominic Thiem was forced to come from behind against home favourite Alex Bolt, with the Austrian eventually winning a five-set thriller.
In the women's bracket, second seed Karolina Pliskova was a routine winner, as was two-time Grand Slam champion Simona Halep.
Here are some of the standout results from Melbourne and a recap of what was another entertaining day at the Australian Open.
Australian Open 2020 - Selected Wednesday Results
(1) Rafael Nadal bt. Federico Delbonis: 6-3, 7-6 (4), 6-1
(4) Daniil Medvedev bt. Pedro Martinez: 7-5, 6-1, 6-3
(5) Dominic Thiem bt. Alex Bolt: 6-2, 5-7, 6-7 (5), 6-1, 6-2
(7) Alexander Zverev bt. Egor Gerasimov: 7-6 (5), 6-4, 7-5
(10) Gael Monfils bt. Ivo Karlovic: 4-6, 7-6 (8), 6-4, 7-5
(2) Karolina Pliskova bt. Laura Siegemund: 6-3, 6-3
(4) Simona Halep bt. Harriet Dart: 6-2, 6-4
(6) Belinda Bencic bt. Jelena Ostapenko: 7-5, 7-5
(9) Kiki Bertens bt. Arina Rodionova: 6-3, 7-5
For the results in full, visit the Australian Open website.
Nadal started his match against Delbonis in a supreme groove and raced through the opening set after taking a solitary break.
In the second set, the top seed let a number of break points slip by and that offered some initiative to his opponent, who pushed the Spaniard to a tiebreak.
While Nadal did eventually come through the breaker, Ben Rothenberg of the New York Times picked up on his break-point profligacy:
He finally grabbed a second at the start of the final set and took full control of proceedings, with Delbonis unable to live with the power and precision of the 19-time Grand Slam winner.
There was also a moment late in the match when Nadal comforted a ball girl, as his return struck her in the head, per Jose Morgado of Record:
Meanwhile, Medvedev looks like he's going to be a serious challenger for the title this year, with Martinez unable to contain him over the course of three sets. After getting a taste of a Grand Slam final at the U.S. Open last year, the Russian has the quality and experience to go far.
The tournament nearly came to a premature end for Thiem, as he battled against a determined Bolt and the Australian crowd to emerge on the right side of a five-set epic.
Afterward, the fifth seed said he enjoyed playing in front of what was a lively Melbourne crowd:
Nick Kyrgios always provides thrills, too, whether that be with his tennis or his antics in between points.
The Australian faced a potentially difficult clash with Gilles Simon and eventually outlasted his opponent over four sets.
Per Wide World of Sports, there was a good spirit between the two men, as they were each administered with time violations:
As Eleanor Crooks of the Press Association relayed, Kyrgios appears to be dialled in on his tennis:
If he continues to win, then there's potential for what would be a fascinating meeting with Nadal in Round 4.
Elsewhere, there were no major surprises in the women's draw, as Pliskova was a confident winner over Laura Siegemund. The second seed is chasing her first Grand Slam title, and the early signs are that she is in the kind of form needed to win this competition.
Halep will be tough to get the better of in Australia, though, as she looks to add to her two major successes. She showed her class to overcome Harriet Dart, who pushed the Romanian hard in the final set.