Reigning champion Raymond van Barneveld edged out Tony O'Shea 5-4 to pick up his second successive Group E victory in the William Hill Grand Slam of Darts.
After trailing 2-0 early on at Wolves Civic, Stockport's O'Shea hit back to lead 3-2, but the Dutchman soon levelled as the pair headed to a deciding leg, which the van Barneveld won with a 72 finish.
There were also wins for Simon Whitlock, Mervyn King, Scott Waites, Ted Hankey and Robert Thornton, who maintained his 100 per cent record in the tournament.
King's high-quality 5-2 win over Ricky Evans in the day's other Group E game means that there is still all to play for going into Monday's final matches.
Van Barneveld would qualify with a win over King, with O'Shea and Evans also still able to win through to the knockout stage of the event in the final set of games.
"I like the group format of this competition and the two wins have helped build my confidence," said van Barneveld. "I hope it will set me up well for the rest of the week.
"I don't ever make it easy for myself, but I managed to produce good finishes towards the end and get the win."
Australian star Whitlock won his second match in Group G in impressive style, averaging 108.78 in a 5-1 victory against Mark Webster, hitting four 180s and missing only one dart at a double.
He is now in pole position ahead of Monday's final game with Wes Newton, who was a 5-2 winner against Ross Smith as he joined Webster on two points.
Waites, the 2010 Grand Slam of Darts champion, became the first player to win through to the second round with a fine 5-2 victory over Michael Smith in Group H, as Hankey kick-started his challenge.
Hankey eliminated Dave Chisnall after producing a fine display to come from 3-1 down to claim a fine 5-3 triumph from their contest.
"I felt pretty decent and it went well for me," said Hankey. "I fed off the crowd and it helped me, I played my natural darts and the 170 was as sweet as a nut.
"I've had my health problems and I've been on the mend, and I know that when I can play I'm as good as anybody and I can do anything."
Scotsman Thornton followed up Saturday's whitewash of Mark Walsh with a 5-2 win over Justin Pipe, taking out a key 152 checkout in the victory.
Groups A-D play their second games at the Wolves Civic on Sunday night, including four-time champion Phil Taylor up against Paul Nicholson, Michael van Gerwen's clash with Dean Winstanley and Adrian Lewis up against Ronny Huybrechts.