Reigning champion Van Gerwen avenged his group stage defeat to Jonny Clayton with a superb 16-12 win over the Welshman to remain on course for a record-breaking fourth straight title.
Clayton, a 5-3 winner when they met last Sunday, lived with the world number one for 22 legs before Van Gerwen pulled clear for victory.
A high-quality opening saw the pair trade 14-darters before Clayton led 2-1 and 4-3, courtesy of a 142 checkout for one of three early 12-dart finishes the pair landed.
Van Gerwen took out 124 as he levelled in leg eight, and also finished 90 and 107 on his way to an 8-6 advantage.
Clayton restored parity with back-to-back 13-darters and took out 110 in leg 20 as he stuck with the reigning champion through to 11-all.
Van Gerwen, though, finally shook off his rival with a four-leg burst to pull clear, finishing 92 and 94 for back-to-back 11-darters and 66 to move a leg away from victory at 15-11.
Clayton punished eight missed match darts from Van Gerwen to keep his hopes alive, but five misses of his own came back to haunt him in leg 28 as Van Gerwen took out 66 once again to seal the win.
“I think I did the right things at the right moments,” said Van Gerwen. “The beginning was phenomenal for both of us, we kept each other under pressure.
“I’m really glad I did it at the end, I had a couple of good legs to take the lead and give myself that confidence.
“My scoring power and doubles weren’t as good as the last games so they have to be better in the next one. I didn’t play my best game but I still averaged 101 and I’m glad that I won.
“Jonny has made some huge steps in this tournament. He beat me in the group and gave me a really good game here as well.”
Looking ahead to his semi-final with Anderson, Van Gerwen added: “For a lot of people it’s going to be the game of the tournament.
“Me and Gary are the best two players in the world and we are going to have a great battle.
“The winner has got a massive chance to win this tournament. We both know that and we need to keep our heads focused tomorrow.
“I could be the first player to win four times in a row, but that’s something to worry about tomorrow.”
Anderson, meanwhile, powered into the semi-finals for a sixth time in 12 years, continuing his impressive week in Wolverhampton with a 16-6 success against Michael Unterbuchner.
The Scot had only dropped six legs in reaching the quarter-finals and was equally dominant against the German newcomer.
BDO qualifier Unterbuchner led 2-0 following an impressive start, opening with a 14-darter and doubling his lead before Anderson – aided by a brilliant 152 finish – took seven straight legs.
Legs of 13 and 12 darts helped Unterbuchner to hit back, and after Anderson fired in checkouts of 101 and 68 as he moved 12-4 up the German ace took out a superb 160 finish.
Unterbuchner also landed a 13-darter to stay in the game at 14-6, but Anderson took out 100 to reassert his dominance before sealing victory on double one, ending the tie with a 100.48 average.
The win moves Anderson, the 2011 runner-up, into his sixth Grand Slam of Darts semi-final as he continues his bid to claim a fifth televised title of the year.
“It was hard but it was easy at the same time,” said Anderson. “I got a good lead and that can be hard sometimes, but there were some good darts in there and I got myself over the winning line.
“Michael didn’t play as well as he did in the last three games – he was great against James Wade but he had some blips tonight. He never got going tonight but he’s done well this week.”
Anderson is now aiming to scoop the £110,000 top prize on Sunday when the semi-finals and finals are held at the Aldersley Leisure Village.
“I’d love to win this event and it’s a tournament that’s close to my heart,” said the two-time World Champion. “It’s well documented that this is my favourite tournament and it’s a good new venue here.
“It would mean a lot to win this because I’ve played here for all 12 years, but we’ll see what happens on Sunday.”
Sunday’s semi-finals will begin with the tie between number six seed Mensur Suljovic and Welshman Gerwyn Price, as both bid to reach the final for the first time.
After Van Gerwen and Anderson meet in the afternoon session’s other semi-final, the tournament then concludes in the evening session with the final at the Aldersley Leisure Village.
The tournament will be broadcast live on Sky Sports and through the PDC’s worldwide broadcast partners, as well as through PDCTV-HD for Rest of the World Subscribers.
Van Gerwen is the 67/100 favourite to scoop the title on Sunday night with sponsors bwin, with Anderson 5/2, Suljovic 6/1 and Price the 11/1 outsider.
2018 bwin Grand Slam of Darts
Saturday, November 17
Gary Anderson 16-6 Michael Unterbuchner
Michael van Gerwen 16-12 Jonny Clayton
Sunday, November 18
Afternoon Session (1300 GMT)
Gerwyn Price v Mensur Suljovic
Michael van Gerwen v Gary Anderson
Best of 31 legs
Evening Session (1930 GMT)
Van Gerwen/Anderson v Price/Suljovic
Best of 31 legs