* Australia reach first semi-finals since 2006
* Groth sets perfect stage for Hewitt's final heroics (Adds details)
MELBOURNE, July 19 (Reuters) - Ageing tour warrior Lleyton Hewitt banished a tumultuous week for Australian tennis by guiding his team into the Davis Cup semi-finals on Sunday with victory in the final singles against Kazakhstan.
Australia will meet either Britain or France for a place in their first final since 2003 after the hard-bitten former world number one trounced Aleksandr Nedovyesov 7-6(2) 6-2 6-3 in the Darwin sunshine.
After Nedovyesov blasted past the baseline to surrender, 34-year-old Hewitt slumped on his back on the grasscourt to deafening cheers from a raucous home crowd before being mobbed by his whooping team mates.
"I love the back-against-the-wall situation. That's what we had after day one," the two-times grand slam champion said in a courtside interview.
"We had to rally together and find a way to get the win.
"I've always said some of my greatest wins are in Davis Cup and some of my toughest losses are in Davis Cup so I'm going to enjoy this one.
"This is what dreams are made of."
Hewitt's win completed a stirring fightback for Australia, who were 2-0 down after the opening day when young guns Nick Kyrgios and Thanasi Kokkinakis, dubbed 'the Special K's' in Australia, both flopped in the singles.
Australia's number one Bernard Tomic was absent, booted from the team after a public tirade against the country's tennis administration at Wimbledon.
But the controversial 22-year-old's arrest in Miami after a noisy hotel room party was to prove a huge distraction and followed further controversy earlier in the week when Kyrgios rounded on the country's high performance chief Pat Rafter with a stinging post on Twitter.
Hewitt will retire after the next Australian Open in January, so guiding his team into the final four for the first time since 2006 will be a treasured moment for a player who has bled for his country since his 1999 Davis Cup debut.
The win was also a triumph for team captain Wally Masur and big-serving battler Sam Groth, who proved the most unlikely of heroes.
The lanky, 68th-ranked Groth combined with Hewitt to win the doubles and returned on Sunday to edge Mikhail Kukushkin 6-3 7-6(4) 4-6 7-6(6) in the first reverse singles.
Masur's selection of Groth in place of Kyrgios was to prove a master-stroke as the late-blooming 27-year-old set up the perfect stage for Hewitt's final heroics.