By Nick Mulvenney
MELBOURNE (Reuters) - For the second time in three years, Tennys Sandgren defied his lowly ranking to send a top 10 seed out of the second round of the Australian Open on Wednesday when he outslugged Matteo Berrettini 7-6(7) 6-4 4-6 2-6 7-5.
The world number 100 felt he rode his luck a little after giving up the third and fourth sets to the eighth seeded Italian young gun with barely a whimper before rallying to snatch his chance of one of the biggest victories of his career.
"It's a top 10 at a slam so it's right up there," the affable 28-year-old American told reporters.
"He played too good in the fourth, kind of beat me up a little bit, so going into the fifth set I didn't feel like I had much momentum ... I think I got away with one there."
Sandgren has been getting away with a good few wins at Grand Slams since he beat ninth seed and former champion Stan Wawrinka in the second round in 2018 and embarked on a stunning run to the quarter-finals at Melbourne Park.
Putting his poor ranking down to his inability to manage his schedule sensibly, Sandgren said he was just getting better at planning his training to peak at the four major tournaments.
"I like these tournaments a lot, it's one of the few weeks where it feels like tennis actually means something," he said.
"Sometimes it feels like you get lost when you are traveling 25-30 weeks of the year. I feel like my game comes together in weeks like this."
The 2018 run, which also included a win over fifth seed Dominic Thiem in the last 16, convinced Sandgren that he had the potential to do well at Grand Slams.
Translating that into outright confidence was another matter entirely.
"Confidence is a very fickle thing," he said.
"It helps to know that you can do something but if you're stick in the woods and you can't really see the sun, it doesn't matter what you've done, if you can't get a good vibe going, your confidence is lost."
Sandgren's 2018 run was soured when his Twitter account came under scrutiny and he was forced to defend himself against accusations of far right political sympathies. He has been in no mood to discuss the incident on his return this year.
Standing in his path to the fourth round is compatriot Sam Querrey, who came out on top in four sets - three of them decided by tiebreaks - when the pair met at Wimbledon last year.
"We're good friends and he's a great player, he got me in a heartbreaker at Wimbledon last year," Sandgren said.
"I think our games match up pretty well, he's got a great serve and I return pretty well. I'm going to have look after my serve."
(Reporting by Nick Mulvenney, Editing by William Maclean)