As the shadows crept across centre court, doubts circled around David Ferrer's favouritism for a record fourth Heineken Open title.
Ferrer may have taken his first step towards history with a 6-4 2-6 6-3 second round win over Taipei's Lu Yen-Hsun, but in his maiden appearance of 2013, the three-time defending champion was severely tested in the near two-hour dogfight.
While some will attribute Ferrer's surprisingly sluggish start to early-season rust, he will need to swiftly regain form, if he is to become the first man in 46 years to win four consecutive titles in Auckland.
Some powerhouse contenders are waiting to preserve Australian legend Roy Emerson's long-held record and leave Ferrer tied with New Zealand great Onny Parun, who won here in 1973, 75 and 76.
In a high-class centre court match, world No 60 Lu had Ferrer battling the odds.
Lu didn't fear the world No 5. He had the Spaniard scampering, breaking him once in the captivating 51-minute first set and then twice in the second to force a deciding third set no-one had predicted.
The capacity crowd warmed to underdog. They couldn't have asked for more.
This was meant to be a stroll in the park for the top seed. Lu had other ideas, proving the tournament is anything but a foregone conclusion.
Wearing his traditional bandana and displaying quick wrists from the baseline, Ferrer never seemed comfortable.
One suspected he would pull away after breaking in the fourth game of the final set but he couldn't shake the unlikely challenger. Lu broke once more and, even though a remarkable upset always appeared out of reach, the crowd's standing ovation painted the picture of a titanic struggle.
Ferrer's 21 win-five loss record in Auckland, and eighth appearance in the final eight, is impressive, but Lu's efforts will have given Slovakia's Lukas Lacko a timely confidence boost for Thursday's quarter-finals.
HAAS SHOWS HIS CLASS
Earlier, third seed Tommy Haas put on exhibition in his straight sets cakewalk over Igor Sijsling to set up a world-class quarter-final showdown with spectacular Frenchman Gael Monfils tomorrow.
It had been 12 years since the former world No 2 German last appeared in Auckland, when he lost the final in 1999.
This 6-3 6-4 win was the perfect way to return.
At 34, and entering his 16th year on the tour, Haas has, clearly, lost none of his competitive drive, or damaging offensive game.
Fifty-six minutes was all the elder statesman, who appeared in superb touch, needed to book his place against Monfils.
Having started last year outside the top 200, Haas is enjoying a golden run, rising to 21 in the world.
He will again need to produce his best to stop Monfils' revival.
That should be the match of the day. Don't miss it.
He kept the entertainment to a minimum - with just one through the legs shot - but crowd-favourite Frenchman Monfils swiftly exposed Greg Jones to keep his colourful presence alive in Auckland.
After yesterday's torrid three set win, Monfils may have wanted to conserve energy. That's the impression he gave Australian surprise package Jones, who progressed after upsetting sixth seed Jurgen Melzer.
Monfils showed Jones was out of his depth, breaking him in the third game of each set and not dropping his own serve.
The former world No 7 needed just over one hour to claim the 6-4 6-2 win.
In a three-set marathon, former champion Philipp Kohlschreiber eventually defeated the determined spirit of Alejandro Falla to advance to his fifth quarter-final in Auckland.
Kohlschreiber, at times, looked a shadow of the player who won the Heineken Open in 2008 but the German's experience and class shone through in the 7-6 (4) 4-6 6-3 win. He will meet Belgian journeyman Xavier Malisse in tomorrow's final eight.
Played in scorching temperatures over 26 degrees, the two-hour 12 minutes slugfest featured many momentum shifts.
In his ninth appearance in Auckland, Kohlschreiber looked best when he stood tall and hit smoothly through the ball.
The second seed took the first set - after Falla failed to catalyse on a 4-2 tie breaker lead - but then double faulted at the end of the second set as the gallant Colombian battler launched a comeback.
The 29-year-old Kohlschreiber ramped up his aggression and accuracy in the deciding set, finally subduing the world No 53.
Earlier, in little over one hour, Sam Querrey outclassed last year's finalist, Olivier Rochus, 7-5 6-3 to advance to tomorrow's quarter-finals.
The well-rested world No 22 American, who, along with the other top four seeds enjoyed a first round bye, produced 18 aces - nine in each set - and only needed three breaks of serve to finish off his Belgian opponent.
Querrey's serve is a lethal asset.
He won 34 of his 36 first-serve points and varied his game well from there, coming to the net and pushing forehand winners.
The 25-year-old demonstrated why the remainder of tournament day sessions are sold out this week.
- Fairfax Media