Top seed Ben Shelton has moved into the semi-finals of the ASB Classic, defeating Roberto Carballes Baena.
In just shy of 1h 40m, Shelton was given a tough task by the Spaniard, as he bids for a second career singles title.
The 21-year-old American sent down seven aces and broke serve three times on centre court at the ASB Tennis Arena, but also double faulted three times across the two sets.
In an evenly matched start, Shelton came up with a crucial break at 5-4, and took the first set as a result.
In the second set, Carballes Baena showed promising resolve to save two break points at 2-2. But once Shelton managed to break at 5-3, the top-seed made no mistake in holding to advance to the last four.
However, there was more bad news for the tournament, as second-seed Cameron Norrie was forced to withdraw with a wrist injury.
On Wednesday, the Kiwi-raised Brit was taken to three sets against Luca van Assche, with the effects of the match which lasted close to two-and-a-half hours clearly taking its toll on the local favourite.
Norrie was scheduled to face unseeded Alejandra Tabilo of Chile, who has been given a walkover into the semi-finals instead.
In the day's opening quarter-final, Japan's Taro Daniel held on to seal his place in the last four, after threatening to throw away what appeared to be a straightforward victory over France's Alexandre Muller.
After taking the first set 6-4, Daniel threw away the second set, dropping it in a tiebreaker after at one point holding a 4-0 lead.
However, Daniel regained his composure in the deciding set to take it 6-3, and advance to the semi-finals to face Shelton on Friday.
In the day's late game, sixth-seed Arthur Fils progressed to the semis, after opponent Daniel Atlmeir withdrew through injury.
Frenchman Fils took the first set in a tiebreak, after more than an hour of play on centre court.
Fils and Tabilo will meet on Friday, after both players' walkover wins sent them into the last four.
