Auckland - Top seeds David Ferrer and Philipp Kohlschreiber both survived scares to reach the quarter-finals of the ATP men's tournament in Auckland on Wednesday.
Defending champion and number one seed Ferrer suffered a mid-match slump as he came under pressure from Lu Yen-Hsun of Taiwan in the warm-up event for next week's Australian Open, eventually grinding out a 6-4, 2-6, 6-3 victory.
"The court was very fast and sometimes I couldn't defend, but anyway, I won the match," a relieved Ferrer said.
Chasing a record-equalling fourth Auckland title, the Spanish world number five made a perfect start by breaking Lu in the second game, aided by three double faults from his opponent.
The dogged Lu broke back seven games later, only for Ferrer immediately to regain his advantage and take the first set 6-4.
But the Spaniard's serve misfired in the second and Lu, ranked 60 in the world, helped himself to a double break, claiming the set 6-2 to force a decider.
Ferrer regrouped and won the set 6-3 to set up a quarter-final on Thursday with Slovak Lukas Lacko, who defeated eighth seed Thomaz Bellucci of Brazil 6-3, 7-5.
Kohlschreiber, the second seed, was also unconvincing and committed 52 unforced errors and four double faults in a rusty 7-6 (7/4), 4-6, 6-3 win over Colombian Alejandro Falla.
The German managed an early break and appeared to be cruising as he raced to a 5-2 lead in the first set before Falla broke back to force a tie-break, which the German comfortably won 7-4.
But Falla, a quarter-finalist here last year, continued to press Kohlschreiber in the second, breaking the world number 19's serve in the 10th game to claim the set 6-4.
Kohlschreiber finally took control to win the third set 6-3, with the German opening up a double break over Falla as his ground shots finally found their range.
"It was very tough, Alejandro played very good points and it was very difficult for me to hang in there," he said. "In the end, I was very happy with my performance."
Kohlschreiber, the 2008 Auckland champion, will face Belgian veteran Xavier Malisse in the quarters.
There were no form problems for former world number seven Gael Monfils, who never looked threatened as he disposed of Australian qualifier Greg Jones 6-4, 6-2.
The Frenchman, whose ranking plummeted to 77 while he was sidelined with a knee injury, was back to his acrobatic best, showing no sign of discomfort as he threw himself around the court.
"Obviously I was moving great, so I'm happy and pleased with my performance," he said.
A wild card entry in Auckland, Monfils lines up against Tommy Haas in the last eight after the German third seed downed Igor Sijsling 6-3, 6-4.
Fourth seed Sam Querrey defeated Belgium's Olivier Rochus 7-5, 6-3 to set up a quarter-final with Jesse Levine of Canada.
Results of the Heineken Open on Wednesday:
David Ferrer (ESP x1) bt Lu Yen-Hsun (TPE) 6-4, 2-6, 6-3
Philipp Kohlschreiber (GER x2) bt Alejandro Falla (COL) 7-6 (7/4), 4-6, 6-3
Sam Querrey (USA x4) bt Olivier Rochus (BEL) 7-5, 6-3
Xavier Malisse (BEL) bt Santiago Giraldo (COL) 7-6 (8/6), 6-4
Lukas Lacko (SVK) bt Thomaz Bellucci (BRA x8) 6-3 7-5
Jesse Levine (CAN) bt Brian Baker (USA) 7-5, 6-4
Gael Monfils (FRA) bt Greg Jones (AUS) 6-4, 6-2
Tommy Haas (GER x3) bt Igor Sijsling (NED) 6-3, 6-4