Pitchford, who had beaten Japan's Koyo Kanamitsu earlier in the day, moved past Germany's 37-year-old multiple world and Olympic medallist, who is still world-ranked 20 places above the Briton at number three, 11-6, 11-6, 5-11, 8-11, 13-11, 12-10.

The 25-year-old from Chesterfield will now await the winner of the quarter-final between China's second seed Xu Xin and Tomokazu Harimoto of Japan.

Xu, a team Olympic champion at Rio 2016, progressed to the last-eight with an 11-1, 11-7, 7-11, 11-2, 11-4 win over India's Sathiyan Gnanasekeran

Harimoto beat compatriot Jun Mizutani 11-6, 11-5, 9-11, 11-8, 11-7.

Meanwhile China's world number one Fan Zhendong booked his men's quarter-final place with a comfortable win over Japan's Jin Ueda.

Fan, who won the Swedish Open last week, came through 9-11, 11-4, 11-2, 11-4, 11-4  in this World Tour Platinum event at the TipsArena.

His opponent tomorrow morning will be another Japanese player, Koki Niwa, who earned an 11-9, 11-7, 11-6, 12-10 win over compatriot Kazuhiro Yoshimura.

The winner of that match will meet Liang Jingkun in the semi-final, with the Chinese player having won his earlier quarter-final against Brazil's Hugo Calderano 11-5, 15-13, 11-4, 11-9.

There was a shock in the women's event also as Ding Ning, China's reigning world and Olympic champion and second seed, was beaten by compatriot Wang Manyu.

The number six seed won 11-5, 9-11, 2-11, 11-8, 11-6, 6-11, 11-7 to earn a semi-final place.

Another surprise result was taking place on the adjoining table as Chinese qualifier He Zhouija won her quarter-final against Chinese Taipei's Cheng I-Ching, the number seven seed, 11-3, 11-5, 11-7, 11-4.

The quarter-final contests in the opposite half of the draw between China's Zhu Yuling and Hong Kong's Doo Hoi Kem, alongside Liu Shiwen and Chen Meng of China, will be played tomorrow.