“It was just my instinct to help her and I think everyone would do the same. I’m happy I got to help.”
When they resumed, qualifier Sonmez stunned Alexandrova 7-5, 4-6, 6-4 for the biggest win of her career.
The 23-year-old made headlines at Wimbledon last year, becoming the first player from Turkey to reach the third round at a Grand Slam in the Open era.
She will play either American wildcard Elizabeth Mandlik or Hungary’s Anna Bondar next.
Temperatures have been known to soar past 40C during the Australian Open.
They are forecast to reach a high of at least 36C this week.