The Nikkei stock index briefly surged over 2 percent Friday morning to a record intraday high above the 52,000 line, lifted by strong tech shares following robust earnings reports by some U.S. technology companies overnight. The 225-issue Nikkei Stock Average gained 622.65 points, or 1.21 percent, from Thursday to 51,948.26. The broader Topix index was up 12.92 points, or 0.39 percent, at 3,313.71, also after setting a new all-time intraday high.