He went on to his third half century in seven test innings against South Africa.
Stephen Cook's miserable match continued when he was caught off the fourth delivery he faced but Dean Elgar and Hashim Amla gritted it out in gloomy weather. Given New Zealand included two spinners in their side, the intentions of what they thought the pitch was going to do were made clear, however with only two wickets between them from 51 overs, dropping Tim Southee in hindsight probably wasn't the greatest option.
A battling Kane Williamson ensured New Zealand took the second-day honours despite a crippling calf injury to senior batsman Ross Taylor in the first Test against South Africa in Dunedin on Thursday.
Maharaj recorded figures of 5-94 on Friday to keep New Zealand in check in their first innings total of 341 - a lead of 33.
Williamson then made a bowling change and it worked wonders as Neil Wagner (2-59) claimed two wickets in one over.
South Africa were in trouble at 22 for three when du Plessis joined Elgar to mount their rescue mission. "But hopefully we can make a game of it, it's always nice to get a result", said South Africa's man of the moment Keshav Maharaj.
Trent Boult, who returned figures of four for 64, dismissed Temba Bavuma for 64 and ended the South Africa innings when he bowled Philander in the fifth over after lunch for 21.
Boult boasted with figures of 4/64 and Wagner 3/88, as New Zealand looked ahead to taking the crease in the middle.
Raval put on 102 for the second wicket with Kane Williamson - the highest ever second wicket stand for New Zealand in Test against South Africa.
The pitch continued to play better and better and even though Tom Latham's torrid form continued at the top of the order (his worldwide scores this year read 7, 0, 0, 2, 0, 10), New Zealand found the going good and scored quickly on a surface that played true and offered little or no lateral assistance for the bowlers after Willaimson ordered the heavy roller to smooth it out between innings'.