Johnson was beaten in the second round, but it was his opening match this year at the tournament because he received a bye as the No. 1 seed. He fell to 4-8 this season. Galan never had won an ATP Tour tournament match until Tuesday in the first round at Houston.
The 22-year-old Galan will face No. 7 seed Jordan Thompson in Friday's quarterfinals. Thompson came back to get past another qualifier from Colombia, 224th-ranked Santiago Giraldo, 4-6, 7-6 (1), 7-5. Giraldo served for the victory at 5-3 in the third set, but Thompson broke him there to begin a four-game, match-ending run.
Earlier Thursday, former top-10 player Janko Tipsarevic reached his first ATP Tour quarterfinal in 2 ½ years by beating No. 3-seeded Cameron Norrie 6-3, 6-4. The 34-year-old Tipsarevic returned to the tour this year after missing 16 months while having operations on his hamstrings.
He is ranked 372nd and entered the Houston tournament via a wild card. He is the lowest-ranked quarterfinalist at the tournament since at least 1979, according to the ATP. Tipsarevic hadn't won a tour-level match since 2017 until doing so at the Miami Open last month. His most recent quarterfinal appearance came at Shenzhen, China, in October 2016.
Tipsarevic next will face No. 8 seed Sam Querrey, who eliminated Guillermo Garcia-Lopez 6-4, 6-3. Querrey won 43 of 54 points on his serve and saved the lone break point he faced.
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