Stephen Hendry hit the front in his long-awaited first Crucible meeting with John Higgins, taking an early 5-3 lead as Scotland's big day in Sheffield arrived.
While Hendry made his debut as long ago as 1986, since Higgins made his first appearance at the Betfred.com World Championship in 1995 they might have gone head to head in any year.
Bafflingly the pair who have 11 world titles between them have avoided each other, but this year's draw offered the opportunity for a second-round tussle.
Hendry had to qualify this year but his maximum break against Stuart Bingham confirmed the 43-year-old as a man in form, and he ploughed in breaks of 81, 69, 93, 123 and 67 to seize a 5-3 lead in the best-of-25-frames tussle.
Higgins, the 36-year-old four-time world champion, took the opening two frames of the match, but neither player looked to have settled down.
Hendry, who won the last of his record seven world titles in 1999, then responded with two classy breaks to draw level at 2-2.
Higgins returned from the mid-session interval to ram in the first century of the match, a rapid 124 to restore his lead, but it was the last frame he won of the session as Hendry reeled off three in a row.
Neil Robertson moved into a 10-6 lead against David Gilbert in the second session of their game, and they will fight it out to a finish on Friday night.