Angry Karatsev edges through in Australian Open epic (VIDEO)

Emotional Aslan Karatsev earned a five-hour first-round win over the world number 71 at the Australian Open, where last year's semifinalist appeared troubled during one of the most eventful matches the tournament has ever seen.

The usually-reserved world number 15, who was named the Most Improved Player of the Year by the ATP in 2021 for his meteoric rise through the rankings, raged at himself as he fell two-sets-to-one behind to Jaume Munar, an opponent who has never been inside the top 50 and is yet to pass the second round of a Grand Slam.

At one point when he was trailing, statistics revealed that Karatsev had produced an astonishing 54 unforced errors to Munar's eight, with a clip from the fourth set showing him uncharacteristically missing the simplest of smashes to drop a point.

By that time, Karatsev was on his way to clawing victory from the jaws of defeat after racing into a 3-0 lead in what threatened to be his final set of the tournament.

Despite his spirited comeback, the 18th seed showed little of the form that took him to a final-four meeting with champion Novak Djokovic last year, spurning a 4-1 lead in the fifth set.

Out-of-sorts Karatsev rallied again to eventually win the deciding set 6-4 after being taken to deuce by Spaniard Munar.

Karatsev's shocking error total is said to have hit a whopping 107 blunders on his way to a gruelling triumph after four hours and 52 minutes of play.

The performance provided a stark contrast to Karatsev's dominant display at warm-up tournament the Sydney Classic on Saturday.

In brushing aside three-time major title winner Andy Murray to lift his first trophy of 2021, the 28-year-old had looked a strong contender to continue his impressive form at the first Grand Slam of 2022

Tennis reporter Jose Morgado called Karatsev's recovery to win a nail-biting second set 7-6 "huge", but added that the Vladikavkaz-born star's count of 26 unforced errors in that set "summed up" the early stages of the mistake-littered showdown.

The Davis Cup winner with his country will take encouragement from the 87 winners he hit to edge through in an epic that was hailed as "amazing" by many viewers on social media.

He will also see abundant room for improvement after a showing that was only seven errors away from the record, accoring to The Tennis Podcast.

The popular site added: "Aslan Karatsev's had better days, but he lives to fight another."

The relieved winner will face American Mackenzie McDonald for the first time in his career in the second round.

A meeting with the world number 55 should make Karatsev the favorite to prevail, although the man who tested positive for Covid at the end of 2021 – delaying his arrival in Australia – will not be taking his progress for granted after a surprisingly difficult start to his campaign.

Top Russian seed Daniil Medvedev and his compatriot Andrey Rublev, who is seeded fourth, play their first-round matches on Wednesday. The tournament continues until January 30 2022.