Lleyton Hewitt holds key to Davis Cup tie in Bernard Tomic's head

KOOYONG -- Midway through his fourth set against U.S. opponent Jack Sock, Bernard Tomic looked like he might let Australia's Davis Cup hopes slip through his sweaty fingers.

Gone was the energetic, calm and confident world No. 20, who'd stormed to a two-set lead against an opponent ranked only four places lower. In his place, a sluggish, flustered version of Tomic appeared, devoid of energy and inspiration and wilting badly underneath the fierce sun.

On his favoured grass court but playing in unfavourable conditions - the mercury soared into the mid-30s at Melbourne's historic Kooyong, although it felt closer to 40C on court - Tomic, and indeed Australia, was in deep trouble when he lost the third set. The ease of which he surrendered it certainly would have worried his captain, the recently retired Lleyton Hewitt.

The home side was already 1-0 down due to John Isner's powerful victory against Sam Groth. Severely weakened by the withdrawal of Nick Kyrgios with a virus, and facing the just-about-unbeatable Bryan brothers in the doubles, Australia's Davis Cup dreams were slipping away faster than Tomic's energy levels.

After dropping the third set, Tomic was still below his best in the fourth but hung tough. But with Hewitt, his teammates, and a boisterous home crowd urging him on, Tomic found something. Suddenly he was chasing balls with renewed vigour. Suddenly he was playing with the poise and precision that had seen him surge two sets clear. It was as if Hewitt had miraculously transported some of his famous fighting spirit to a flagging Tomic.

Tomic said having Hewitt - Australia's most successful Davis Cup player - courtside helped inspire him as he reclaimed his grip on the match, which he eventually won 7-6 (7-2), 6-3, 3-6, 6-4. It was a victory that took Tomic's incredible Davis Cup singles win-loss record to 16-3.

"[Hewitt] was saying the right things and the positive things that were motivating me each game, because I was losing a lot of games very, very comfortably on Jack's serve so he was encouraging me so much and saying the right things," Tomic said post-match.

"For me it was an amazing situation to be a part of; the first time Lleyton was in the chair for me, playing by his side is something new and something I respect, and it really was a great honour."

Hewitt said he was proud of the way the big Queenslander fought back.

"It's about how you respond ... and he found a way in the fourth set," Hewitt said. "It's not an easy thing to do to come out when you're the No. 1 player for your country and you're one-love down in a Davis Cup World Group match. . "Bernie did fantastic today."

The contrast between Friday's two opening singles matches was as stark as the weather change that stormed through Kooyong only minutes after Tomic had levelled the tie.

If the combatants changed rackets for boxing gloves, Groth and Isner were the brutal heavyweights, going toe-to-toe trying to land quick knockout punches. Tomic and Sock, meanwhile, were light-footed welterweights, dancing around the court, swinging dazzling combinations before retreating, planning their next attack.

Tomic eventually won convincingly on points - his first in four attempts against Sock.

But for the home team to win the tie and progress to the quarterfinals, Tomic will surely have to break another duck - against Isner, who defeated the Australian in their only previous contest.

How Tomic's guile and court craft - and mindset - shape up against the incredible power of the American could decide this tie between the Davis Cup's two proudest nations.