Matthew Stevens produced a clinical display to open up a 4-0 lead over Tony Drago at the Embassy World Championship in Sheffield.
Stevens took the opening frame 99-43, and it was the Welshman who registered a 57 break to race into a 2-0 lead.
The 23-year-old, who beat Drago 10-2 at the Crucible last year, opened up a three-frame advantage after winning a tactical battle with the Maltese break-builder.
Drago had an opportunity to pull a frame back before the mid-session interval, but he was unlucky to finish close up to the black after forcing in the pink down a cushion.
The frame would be decided by the black, and it was world number six Stevens who knocked in the last ball to leave Drago deflated at the break.
On the other table, Australia's great hope Quinten Hann produced a spirited fightback to square his match with Dave Harold.
Harold knocked in a break of 59 to clinch the opener, but Hann hit back with a 67 break to grab the second.
Harold, the world number 13 from Stoke-on-Trent, edged out the 23-year-old in the third frame with some consistent scoring.
But Hann, who should have cleared the table when on the colours, held his nerve to level at 2-2.