Australian Sam Groth defeated Tim Smyczek 6-3. 6-4 in the semifinals of the Knoxville Challenger this afternoon in perhaps one of the best performances of his career. The win propelled the big-serving Aussie into his fourth ATP Challenger final of the year against second-seeded Frenchman Adrian Mannarino on Sunday. Groth, seeded No. 3, will be looking for his second career title on the Challenger Tour, having hoisted his maiden trophy at Rimouski in March. It’s been quite a year for the globetrotting Groth, who started the year ranked No. 172 in the world and goes into tomorrow’s final a career-high No. 81. In addition to his 22-10 record on the Challenger circuit, Groth has posted a 10-13 mark in ATP Tour-level events, reaching the quarterfinals at Brisbane and the semis at Newport. The No. 98-ranked Smyczek didn’t have enough firepower to stay with Groth, who served big, as he always does, but also blistered service returns, particularly on the American’s second serve, keeping the Milwaukee native constantly on the defensive. Smyczek won just three of 21 points on his second serve. Groth, who often has patches of inconsistency on the ground, was well-nigh flawless on both wings in the first set, while tapering off only slightly in the second. The 27-year-old Aussie broke Smyczek in the opening game of the match and again in the ninth to jump out to a quick one-set lead. Groth got another break in the second game of the second set and raced to a 4-1 advantage, despite three double faults in his three service games. Smyczek managed to draw even at 4-4, after Groth gave back his service break in game seven while committing two more double faults. Groth held for 5-4 and then broke the American in the ensuing game to take the set and match. The Australian served eight aces, double-faulted five times, and saved two of three break points.