The Taiwanese world number 61 was solid on serve and managed to survive 12 aces from the South African to walk away with a 7-6 (8/6) 6-3 triumph in 78 minutes.
Lu, who will now contest his second quarter-final of the season, paid tribute to Anderson after the match, telling the ATP Tour website: “He’s a great player, and you can not give him any chances. All the match I was really concentrating… this match has made me get a little bit of confidence back for the year.”
Fresh from finishing as runner-up in last week’s Memphis Open, Anderson explained that he was not at his best but credit should go to Lu.
“I felt a little bit out of sorts, but I felt like he stuck to his game plan,” the world number 15 said. “It wasn’t the best match.”
Lu will face Adrian Mannarino in the last eight after the Frenchman put in a resolute display to end American wild card Denis Kudla’s hopes in Las Vegas.
Fifth seed Mannarino was strong on serve, winning 76 per cent of points, and saved both break points he faced as he won 6-2 6-2 in 59 minutes.
“It was a good thing for me that the conditions were very cold and pretty slow because I was able to move very well on the court, and Denis was missing a little bit more than me,” Mannarino said.
“I was concentrating on winning one match. Yesterday, I was really happy after my match, and I was like, let’s continue in the next match. I was able to win one more, and I’m just going to take it match after match.”
Steve Johnson is the first American through to the quarter-finals and he will lock horns with Croatian Ivo Karlovic for a place in the semis after they both won on Wednesday.
Johnson breezed past Russian teenager Andrey Rublev 6-3 6-3, while fourth seed Karlovic battled to a 7-6 (7/4) 7-6 (7/2) margin over Australian qualifier Thanasi Kokkinakis.