Konta, the No. 9 seed, first made her mark at Melbourne Park in 2016 when she reached the semifinals, and previous year she made the quarterfinals.
She celebrated by twirling, waving and blowing kisses to the crowd.
The heat was intensifying earlier when six-time champion Novak Djokovic extended his personal streak against Gael Monfils to 15-0 with a 4-6, 6-3, 6-1, 6-3 victory in which both players slouched over in the shade at the back of the court between points. "So I am happy to be here, happy that I'm on court again", he said.
The Russian, beaten in three sets by the Latvian at the US Open a year ago, won 6-1 7-6 (7-4) in one hour and 20 minutes.
Her ranking slid into the 20s in 2017, but she's coming back into the kind of form which makes her a title contender. "Well I did have various emotions, mostly good ones: excitement, joy, gratitude for being able to have an opportunity to compete", Djokovic said Tuesday. "Something is going on with Australia and me".
When Djokovic pulled out of warm-up tournaments in Abu Dhabi and Doha because of pain in his right elbow, there were doubts over whether he would be fit enough to play at Melbourne Park, where he shares the record of six titles with Roy Emerson.
"But I used my experience of being in these particular circumstances so many times in my life and that enabled me to keep my focus and start off well with the right intensity".More news: Jon Gruden, Raiders ready to take on their unfinished business
Kerber had a standout 2016 when she won in Australia, beating Serena Williams in the final, to become the first German since Steffi Graf in 1999 to claim a Grand Slam.
No. 21 Albert Ramos beat US wild-card entry Tim Smyczek 6-4, 6-2, 7-6 (2).
No 4-ranked Alexander Zverev and No 7 David Goffin advanced, but No 20 Roberto Bautista Agut lost to fellow Spaniard Fernando Verdasco, a semifinalist here in 2009, and former Wimbledon finalist Milos Raonic lost 6-7 (5), 7-5, 6-4, 7-6 (4) to Lukas Lacko.
No. 13 Sam Querrey restored some order for the US men with a 6-3, 6-4, 6-2 win over Feliciano Lopez, advancing to the second round. No. 8 Jack Sock and No. 16 John Isner went out in the first round.
The 13th-seeded Querrey was one of 10 American players - men and women - to reach the second round from the 32 who started the main draws, the lowest number of Americans through to the second round in Melbourne since 2011.
Johanna Konta cruised through her first-round match against Madison Brengle.
German Andrea Petkovic won the final three games to beat two-time Wimbledon victor Petra Kvitova 6-3 4-6 10-8 in a thrilling first-round encounter, which lasted two hours and 52 minutes. The US women had three wins and 14 losses in round one.
Halep battled back to take the first set in a tiebreaker and despite going over on her ankle early in the second, she saw the match out comfortably to win 7-6 (5), 6-1. "Despite winning our last match, I faced two match points and barely got through that one, 7-6 in the third".