World number seven KG Montjane delivered a commanding performance to win her second successive women's singles title at the Airports Company South Africa (Acsa) Gauteng Open, but top seed Shingo Kunieda had to work much harder than expected to lift the men's title against Argentina's Gustavo Fernandez on Sunday.
Third-seed Montjane beat top-seed Griffioen in straight sets 6-4 6-1 at the Gauteng East Tennis Centre in Benoni, while world number one Kunieda briefly lost his bearings in the first set before running out a 7-6 (7-2) 6-1 winner over second-seed Fernandez in the Grade I NEC Wheelchair Tennis Tour event.
Montjane had never beaten the Dutch player before, but she wrapped up the first set 6-4 in 28 minutes after making the crucial break in the 10th game.
The South African star then rushed to victory in less than an hour after two breaks of serve in the second and sixth games of the second set.
"I have to admit that I was very nervous about this match against Jiske," Montjane said afterwards. "I had never beaten her and she is a very experienced player. My coach Holger Losch told me to just play my own game and to get a little more aggressive.
"As soon as I realised that she was struggling with her serve and rhythm, I started putting pressure on her with my returns. She also struggled with her forehand, so I hit a lot of shots to her forehand to raise the pressure.
"After I won the first set, I felt hopeful that I could win the match. I just kept piling on the pressure and I went all out to win."
An injury in August derailed Montjane's Paralympic dreams and she launched her come back only recently in January, reaching the quarter-finals of the Australia Open and becoming the first African to compete in a wheelchair tennis Grand Slam event.
In March, she underlined her growing stature when she reached the finals of the women's singles and doubles at the Pensacola Open in the United States.
"It's been a long road back, but it is really fantastic to play at this level again after all the injuries, and to win again," Montjane said.
"This victory has given me a lot of confidence going into the Acsa SA Open next week. It's a Super Series event on the NEC Wheelchair Tennis Tour and it carries a lot of world ranking points. I would really like to do well next week."
Japanese star Kunieda was 0-3 down to Fernandez in the opening set, but the world number one managed to dig himself out of the hole with some aggressive shot play and levelled the score in the sixth game.
After winning the tie break, the Japanese player was back to form and cruised to his first victory on South African soil after breaking the Argentinean teenager's serve in the second game.
"I let Gustavo take control in first couple of games," Kunieda said. "When I got more aggressive and I took more risks, I made a comeback to level the match. I made more first serves and less unforced errors and I took control of the match.
"I got a lot of confidence after winning the tie-break and everything felt good after that."
A three-time Paralympic gold winner, Kunieda arrived in South Africa having won three titles this year in Sydney, Melbourne and Rotterdam. His 382nd men's singles victory also extended his unbeaten sequence on the NEC Wheelchair Tennis Tour to 40 matches since mid-June last year.
Looking ahead to the Acsa SA Open, Kunieda said he needs to work on a few things, but he hopes to win back-to-back titles.
"Of course, I want to win next week, but you saw in the final with Gustavo, it's not always easy. I have to work on a few things. My confidence is high because I have had a good year so far. I definitely think I can make it to the final."
World number one David Wagner initially struggled against second seed Andy Lapthorne, but the American prevailed to win the quads' singles final 6-3 6-4.
Germany's Lucy Shuker and Whiley won the women's doubles final against Montjane and Katharina Kruger of Germany in straight sets 6-1 6-4, while men's first seeds Michael Jeremiasz from France and Britain's Gordon Reid defeated second seeds Fernandez and Frenchman Frederic Cattaneo 6-3 7-5.