Carlson took a 2 up lead on No. 15 with a conceded birdie after he stuck his approach shot on the par-4 close.

Meyer kept his hopes alive with a gutsy halve on the 16th before Carlson closed out the match on No. 17.

Following the rain delay Carlson won an improbable six of eight holes to flip the match.

In the semifinals Carlson will match up against the highest remaining seed, No. 28 Curtis Luck of Australia. Luck, the seventh ranked amateur in the world was able to outlast No. 61 Sahith Theegala 2 up.

Through the first 11-holes of the match the two traded 1 up leads and with eight holes to play everything was all-square.

Luck then rattled off wins on the 12th and 13th holes to take a 2 up lead, only to have Thegala even the match with victorious on Nos. 15 and 16. The win on the No. 16 came via a birdie as the Pepperdine sophomore drained yet another clutch putt, something he had done all week long.

With the match all-square once more Luck, the 2016 Western Australia Open winner, responded like an amateur who has played in a number of professional events should. First he birdied the 17th to take the lead before clinching a final four berth with a par on the closing hole.

Talking about the large crowds that should be following his semifinal match with Carlson, Luck said, "It's always good to have a crowd, I'm looking forward to it. We'll just see. Hopefully, maybe I'll have to give them something to clap about even if they don't want to. That's how it is. I understand, being from Michigan, he's going to have a big following. And it's great to see he's got such a massive crowd supporting him this week.”

No. 31 Jonah Texiera of USC won five of the first seven holes in his match to take a commanding 5 up lead in his 3&2 quarterfinal victory over No. 10 Luis Gagne. LSU's Gagne would try to rally and he did pull within 2 down thanks to wins on the 9th, 11th and 12th holes but Texiera proved to be to much.

After a halve on the 13th and 14th holes Texiera extended his lead back to 3 up with a 15th hole par that moved the match to dormie.

Gagne needed to win the 16th but after both players parred it was Texiera who got into the field after finishing as the first alternate in sectional qualifying advancing.

Texiera will be facing the highest remaining seed in the semifinals, No. 38 Brad Dalke who bested No. 62 David Boote 3&2. The Oklahoma sophomore came surging out of the gates with four consecutive birdies as he took a 3 up lead.

Boote would hang tight getting within 2 down on a couple of occasions, however Dalke playing on his birthday rolled in a number of momentum sustaining putts throughout the afternoon as he closed out the match with a birdie on the 16th.