Ward chose to play Eastbourne rather than Wimbledon qualifying
British number five James Ward stunned world number 72 Rainer Schuettler 6-3 7-6 (7-5) to reach the last eight at the Aegon International in Eastbourne.
Wildcard Ward, who is coached by former British number one Greg Rusedski, broke the German's first service game and the ninth to take the opening set.
The second set went to a tie-break after Ward, 23, had seen four match points slip by in the 10th game.
But he converted his seventh match point to seal victory in the tie-break.
In the previous round Ward had beaten Feliciano Lopez, conqueror of Rafael Nadal at Queen's Club last week, and he said: "Feliciano's ranked higher but Schuettler been as high as five in the world and has been on the tour for years, it was a great win."
Ward will next face Ukraine's Alexandr Dolgopolov, who beat Yen-Hsun Lu 6-7 (1-7) 6-1 6-2
Wednesday's victory was Ward's third at Tour level, following his success against Lopez and a win in round one at Eastbourne in 2009.
"It's only two matches so far, I beat the big names of the tournament, but lesser-ranked players are often hungrier," Ward told the LTA website. "I watched Dolgopolov against Baker, so I'll talk to my coach see how I get on.
"I backed myself to do well today, I can't look back too much. Hopefully I'll continue to have a good week this week, it's all about experience on the big courts at the big events."
The Londoner decided to play at Eastbourne in a bid to boost his ranking rather than attempt to qualify for Wimbledon.
In other matches, top seed Nicolas Almagro was stretchered off with a hip injury when trailing 6-4 1-0 against Denis Istomin of Uzbekistan, while third seed Gilles Simon of France beat Andrey Kuznetsov 6-1 6-7 (3-7) 7-6 (7-2).
Frenchmen Julien Benneteau and Michael Llodra both made it through after wins over Dudi Sela and Stephane Robert respectively.