Stan Wawrinka fought off five match points, but could not stop falling to a fourth successive defeat to Kevin Anderson, slipping out of the Aegon Championships in the second round.

Second seed Wawrinka was unable to extend the fine form that saw him sweep to the Roland Garros crown - even despite again sporting those infamous plaid shorts - with Anderson triumphing 7-6 (7/4) 7-6 (13/11).

The 30-year-old Swiss star had enjoyed stunning form on clay, dispatching huge favourite Novak Djokovic in Paris to seal his second grand slam triumph.

Big-serving South African Anderson dumped four-time champion Lleyton Hewitt out in the first round on the Australian crowd favourite's last-ever Queen's appearance.

And now the 29-year-old from Johannesburg has dismissed another star with a big following at the west London tournament.

Anderson fired down 22 aces but still needed two match points on his own serve - and six in all - to edge home in the second of two tie breaks.

Anderson will now meet the winner of Alex Dolgopolov and Guillermo Garcia-Lopez in the quarter-finals.

Meanwhile, seven-time winner and top seed Roger Federer defeaedt Ernests Gulbis in straight sets to move into the quarter-finals of the Gerry Weber Open.

Federer and Gulbis had gone to a decider in each of their last four tour meetings, winning two apiece, but Federer was a straightforward 6-3 7-5 victor in Halle, where he is defending champion.

Next in the Swiss' sights is German Florian Mayer, who progressed with a 6-3 7-6 (7/4) win over Steve Johnson.

Third seed Tomas Berdych and eighth seed Ivo Karlovic also made safe progress and will meet in the last eight.

Berdych brushed aside Borna Coric 6-3 6-2, while Karlovic dropped a first set tie-break "to wildcard Alexander Zverev before winning the next two 6-3.