Top seed David Ferrer’s consistency was again on show as the Spaniard eased into the Auckland Tennis Classic semi-finals with a straight-sets victory over Czech Lukas Rosol.

World No.8 Ferrer won 6-3 6-4 in 71 minutes against the 54th-ranked Rosol on Thursday.

The 33-year-old Spaniard, who is seeking a record fifth Auckland title, has now made it into the semi-finals seven times in his 11 appearances in the tournament.

A wildcard entry after his early exit from the Qatar Open last week, Ferrer had a first-round bye and then beat Australian qualifier Matthew Barton in the second round.

“It was a good victory,” he said of his performance against Rosol.

“Playing well and better than the first day.”

Asked about the difference between a player in the top-10 and one outside, Ferrer cited consistency.

He said it was key for him, adding that “it’s my game”.

“The most important is my concentration about the match and trying to be focused point by point.”

Ferrer broke Rosol’s serve twice to take the first set.

But neither player created a break opportunity in the second before the match suddenly ended as Rosol, serving at 4-5, lost the game to love.

“The second set, it was a very good match, very good points, and Lukas was pressing me a lot,” Ferrer said

“It was not easy for me. I took my chance in the last game.”

Ferrer will face unseeded American Jack Sock on Friday for a place in the final.

The pair have met once before, with Ferrer winning in Stockholm in 2013.

Sock, 23, booked his spot by upsetting fourth seed Kevin Anderson of South Africa 1-6 6-4 6-4.

The big-serving Anderson, the world No.12 and a semi-finalist 12 months ago, raced through the opening set, not once facing a break point.

But world No.26 Sock came back into the match as Anderson lost his accuracy with his first serve.

Following Anderson out was third seed and two-time champion John Isner, the American losing to eighth seed Roberto Bautista Agut.

The Spaniard won 7-5 2-6 6-3 to avenge his semi-final defeat to Isner in 2014, when the latter went on to claim his second Auckland title.

Bautista Agut will meet the winner of the day’s final singles match between French No.2 seed Jo-Wilfried Tsonga and sixth-seeded Italian Fabio Fognini.