Juan Martin del Potro overcame a stubborn challenge from David Ferrer to clinch their semifinal 6-4 6-4 and advance to a title showdown against Roberto Bautista Agut in the Auckland Classic on Friday.
Del Potro, the 2009 US Open champion and Auckland victor, beat Ferrer 6-4, 6-4 to continue his strong form from the end of last season, which included victory in Stockholm and losing the Basel final to Roger Federer.
In what proved a sterner test than his first-up victory against equally youthful Denis Shapovalov, del Potro on Thursday dominated all of the key moments to win 7-6 (7-4) 6-3.
Instead of that, Del Potro broke again in game 7 when his rival placed a forehand long, and that was all he needed to clinch the opener after 2 good holds and a forehand victor in game 10 for a 6-4.
He broke late against a scampering Ferrer to earn a 6-4 first-set win before seizing another crucial break at 4-4 in the second set and serving out the match.
"I tried to play consistent and aggressive because, with Chung, he plays with power, and it's never easy", Ferrer said afterwards on court.More news: Florida plagued by herpes-riddled monkeys that can kill humans
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Del Potro - who'll head into the final as a red-hot favourite - hoped to lift the trophy once again, as he gears up for a 2018 Australian Open tilt.
"I like to play here, I feel good being here in Auckland".
"I was surprised by the match today", said Del Potro, who had lost to Shapovalov in Montreal last August.
Top-seeded and defending champion Jack Sock bowed out of the ATP Tour's ASB Classic in its second round Wednesday, beaten 6-3, 6-3 by unseeded German Peter Gojowczyk on a bad day for American players.
"Today the conditions were hard and he was a hard opponent, serving very well and a lefty, playing with a very flat backhand", Bautista Agut said.