Lleyton Hewitt will aim for a third win of the year against John Isner when they meet in the semi-finals of the BB&T Atlanta Open.
The pair have played on a hardcourt at Indian Wells, on grass in the semi-finals at Newport, Rhode Island, and another clash on a hardcourt awaits when Hewitt, one of the finest returners in the game, takes on serving colossus Isner for a place in Sunday's final.
In their two clashes so far in 2013, Hewitt has lost tight opening sets before recovering to win, and it would be a surprise were it to be anything but close again.
Australian seventh seed Hewitt started sluggishly against Croatian third seed Ivan Dodig in their quarter-final but improved to win 1-6 6-3 6-0, while top seed Isner saw off fellow American James Blake 7-6 (7/1) 7-6 (7/5).
On the opposite side of the draw, Ryan Harrison's fine week continued as the 21-year-old US player edged his Colombian opponent Santiago Giraldo 6-3 3-6 7-6 (7/2).
Harrison has slumped from 43rd in the world rankings to 132nd as his form and confidence have ebbed away, but he has found a groove this week and could pose an awkward obstacle for South African Kevin Anderson, the second seed, who mastered Denis Istomin of Uzbekistan over three sets.
Anderson won 6-3 3-6 6-3 in one hour and 50 minutes of a match in which both men fired down 12 aces.