With Bernard Tomic overlooked for the tie amid a deep form slump, Hewitt sprung a couple of selection surprises over the weekend, neither of which paid off.
"He says one thing and he does the other. And he contradicts himself all the time," said Nick Kyrgios.
Kyrgios and Australia play Belgium in the semi-final in Brussels this weekend, looking to secure their first trip to the decider since their 2003 win over Spain.
Shapovalov is the youngest man in the third round of a Grand Slam since Bernard Tomic at the 2011 Australian Open and at the US Open since Donald Young in 2007.
US Open 2017, Day 1 highlights: Caroline Wozniacki's unreliable scouting skills to Denis Shapovalov's 'Shapo-fashion'
Here are some off-court highlights from the opening day of the year's final Grand Slam, US Open 2017.
US Open 2017: Bernard Tomic says he's 'not the smartest person' but doesn't regret his controversial outbursts
"But I was honest with my opinions. Sometimes it's better to be honest rather than hiding it and not telling your thoughts," said Bernard Tomic.
Pundits see little chance of Tomic having the required fitness to win best-of-five set matches at the US Open and his childhood coach Neil Guiney fears Tomic's career is finished.
Australian star Bernard Tomic admits he's playing tennis just for money, has no love left for the game
Bernard Tomic was axed by his racquet sponsor just hours after his Wimbledon fine, deeming his behaviour unacceptable.
Wimbledon 2017: From bored Bernard Tomic to struggling Indians, the biggest taking points from Week 1
In the first week of a Wimbledon tournament low on drama, while most of the marquee names made it to the second week, here are the things that caught our eye.
Wimbledon bad boy Bernard Tomic was axed by his racquet sponsor just hours after he was fined £11,600 ($15,000) on Thursday for his controversial post-match rant.
Wimbledon bad boys Bernard Tomic and Daniil Medvedev have been fined for "unsportsmanlike conduct" following their controversial behaviour at the All England Club.
Once heralded as the future of Australian tennis, the only reputation Bernard Tomic and Nick Kyrgios have so far developed is for tanking matches.
Wimbledon 2017: Bernard Tomic says he has lost 'commitment to work hard' after loss to Mischa Zverev
Bernard Tomic has won three titles, breaking through to win in Sydney in 2013 before claiming consecutive titles in Bogota, Colombia, in 2014 and 2015.
Wimbledon 2017: Arina Rodionova upsets Anastasia Pavlyuchenkova to become sole Australian in Round 2
Australia's Arina Rodionova dumped out Russian 16th seed Anastasia Pavlyuchenkova 6-3, 6-7 (6/8), 9-7 in a rollercoaster encounter, taking it on her own fifth match point.
Dan Evans was suspended after admitting last Friday he had failed the test at the Barcelona Open in April.
Despite 16 aces, Grigor Dimitrov failed to convert any of his three break-point chances and was eventually knocked out.
The first day at Roland Garros saw the inspiring Petra Kvitova triumph in an emotional comeback while World No 1 Angelique Kerber lost to Ekaterina Makarova in the very first round. But let's take a look at some of the off court stories.
Dominic Thiem defeated Bernard Tomic in his first round at Roland Garros, and he may have played the point of the tournament in the process.
Dominic Thiem seen as an outside contender for the title after reaching last year's semi-finals at Roland Garros, powered past Tomic 6-4, 6-0, 6-2 in just 80 minutes.
Bernard Tomic, whose world ranking has plummeted to 43, went down to Argentine Diego Schwartzman, 1-6, 6-7(3).