Top seed David Ferrer has eased into the Auckland Open semi-finals, beating Czech Lukas Rosol in straight sets.

The Spaniard, the world No.8, won 6-3 6-4, taking just 71 minutes to get past his 54th-ranked opponent on Thursday.

Ferrer broke Rosol’s serve twice to take the first set, but the second set was tighter, with neither player creating a break opportunity before the match suddenly ended.

Rosol, serving at 4-5, lost four points in a row to depart the tournament.

The 33-year-old Ferrer, 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.

He will next face unseeded American Jack Sock. The pair have met once before, with Ferrer winning in three sets in Stockholm in 2013.

Sock, 23, booked his spot in the last four by coming from behind to upset 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 in Auckland 12 months ago, raced through the opening set, not once facing a break point.

But as Anderson lost his accuracy with his first serve, the second set became more even and looked headed for a tiebreak.

Serving at 4-5, Anderson had his serve put under pressure for the first time and he failed to hold.

The third set was likewise tight and on serve until Anderson was again serving at 4-5.

He saved one match point with a solid serve but world No.26 Sock converted the second to progress to his first Auckland semi-final.