'Sinner's prayers answered': Extreme heat causes chaos, but hands reigning champ a lifeline

(Getty/Hannah Peters)

Day 7 of the Australian Open has been plunged into complete carnage, with play suspended on the outside courts due to extreme heat.

Knowing that Saturday was going to reach a top of 38 degrees, tournament organisers sprang into action early by pushing forward the schedule by half an hour to commence at 10:30am instead of 11am.

But just after 2:30pm, the Australian Open confirmed that the Heat Stress Scale had surpassed 5.0, meaning extra measures have been placed to protect player and fan welfare.

Play on the outside courts will not continue before 5:30pm, with 35.3 degrees the offical temperature in Melbourne around the 2:30pm mark.

The First Serve Live returns on Monday February 2nd at 8pm AEDT for its 18th year on the SEN Network/App, Australia's only dedicated weekly tennis program on commercial radio running through till the end of November.

On Rod Laver Arena, back-to-back champion Jannik Sinner is currently fighting to stay in the event, after dropping the first set to 24-year-old American Eliot Spizzirri before salvaging the second set.

In the opening set, Sinner was broken three times; two of them to love.

The real scare for Sinner fans came midway through the third set when the Italian star was cramping in the corner for nearly two minutes, talking to his team on court, including Darren Cahill.

Sinner, the No.2 seed, received a warning for a serve clock violation, before dropping serve to trail 1-3 in the third.

However, he was handed a lifeline when play was briefly suspended to close the stadium roof, allowing Sinner to regroup. As action resumed, Sinner broke back, but called the trainer down 3-4 on serve.

Sinner managed to win five of the next six games after the break to close the roof, leading two sets to one.

Both Sinner and Spizzirri went into the locker room for a 10-minute break at the completion of set three due to the difficult conditions.

In the end, it was the four-time major champ who prevailed in a closely fought 4-6, 6-3, 6-4, 6-4 victory.

He admitted during his on-court interview that he “struggled a bit physically today” and that he was “lucky with the heat rule” coming into effect when it did.

This time last year, Sinner caught a lucky break when one of his powerful serves somehow managed to break the net, causing a 20-minute delay when Sinner was up two sets to one against Holger Rune in the fourth round, admitting he felt a "bit dizzy".

The First Serve Live returns weekly each Monday Night on the SEN Radio Network & SEN App.

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