Rotorua had lost to Hamilton twice this season heading into the game on Saturday, but Simpkins said they had learned a lot from those previous two outings.
He said they showed a lot more urgency and less panic this time around. "Our urgency at the ruck and our decision making under pressure - those were two key [areas], but we also brought some real aggression to the game."
Trailing by seven points, Hamilton had about five minutes of possession on the Rotorua try line at the death but could not find a way through the visitors' defence.
"We were under pressure in the dying minutes, it seemed like a long time, and that showed a lot of character from our guys," Simpkins said.
Rotorua keep their season alive for another week with the victory while Hamilton's season has come to an end.
If Rotorua win this coming weekend against New Plymouth Boys' High School they will qualify for the National Top 4 competition, being held in Rotorua next month, and keep their hopes of winning a national title alive.
New Plymouth defeated Wesley College (South Auckland) 20-15 at the weekend to progress to the Chiefs region final alongside Rotorua.
Simpkins said there would be a lot of smiling faces at training this week but they would quickly turn their attention to New Plymouth. "We are one win away from making the top four at our home ground, so we will be chucking the kitchen sink in this week."
The match against New Plymouth will most likely be played in Taranaki despite some controversy about who should get home field advantage.
Rotorua's try scorers on Saturday included Trent Harris, James Tofa, Jaya More and Waisea Niumataiwalu.
-Western Heights High School 1st XV play in a big match against Stratford High School (Taranaki) on Wednesday at Western Heights at noon, as they chase a spot in the National Top 4 co-ed competition.
