Kei Nishikori advanced to the quarterfinals of the Swiss Indoors with a straight-sets win over Paolo Lorenzi on Wednesday.
In his second match back since suffering an injury at the Japan Open in early October, world No. 5 Nishikori made 18 unforced errors in the first set but cleaned up in the second to overcome the plucky 38th-ranked Italian 7-6 (7-3), 6-2 in 98 minutes.
"There was frustration," Nishikori said of the first set in which he squandered a number of break opportunities.
"I missed break points time after time and that made things difficult. But I was able to put pressure on my opponent and the chances kept coming," added the Rio Olympic singles bronze medalist.
Nishikori reduced his errors in the second set and after winning his first break point in the third game, the 26-year-old never looked back.