World number one Lee Westwood recorded another comfortable win to book a match with Ian Poulter in the last 16 at the World Match Play Championship in Spain.
Westwood had seven birdies in 10 holes to beat Aaron Baddeley 4&3, while Luke Donald and Martin Kaymer also won.
Nicolas Colsaerts beat Retief Goosen and Rory McIlroy but McIlroy qualified to face Graeme McDowell on Saturday.
Poulter went through after halving for the second day running, although world number nine Paul Casey bowed out.
The players were divided into eight groups of three, with each playing each other over the opening two days and the top two progressing to the last 16 when the event reverts to a straight knockout format.
Surprisingly only one trio required a sudden death play-off after all three finished on the same number of points.
That saw Miguel Jimenez eliminated at the first extra hole and at the next Johan Edfors hooked his second into the shrubbery as Masters champion Charl Schwartzel took top spot.
Edfors will play world number two Luke Donald, who had five birdies in a 3&1 victory over Ross Fisher, who earlier overturned a three-hole deficit with four to play against American Ryan Moore.
Casey, who lost to Avaro Quiros on Thursday, was three down after three holes to Denmark's Soren Kjeldsen, but levelled the match after winning three out of four holes from the eighth.
However he three-putted the 12th and lost three in succession, and despite winning two consecutive holes, the final two holes were halved.
Vegas, who became the first Venezuelan to win an established event at the Bob Hope Classic in January, had four birdies on the back nine, including a conceded putt from inside three feet at the 16th following a magnificent escape from a fairway bunker.
That reduced McDowell's lead to one but the 17th was halved in par threes and the Northern Irishman topped the group courtesy of his victory over Open champion Louis Oosthuizen on Thursday.
Vegas had beaten Oosthuizen in the morning matches, making four birdies in the final seven holes having been two down after three.
Looking ahead to his match with world number six McIlroy, McDowell, currently ranked fifth, said: "He beats me every time we play together.
"But this is the Northern Ireland match play championship and I'm hoping it's going to be different. It's the Volvo World Match Play and the pressure is on.
"I am sure he will expect to beat me, but it will be a great game and I am excited about it.
"He is a fabulous player, so talented. This course is all about driving the ball and he is pretty good at that.
"It's hard to play against a close friend, but you've got to leave your friendship on the sidelines. I stopped playing him because he's too good. I'm more of an observer and he just tends to beat me up. I've just got to hang tough with him."
Friday morning results:
A Baddeley (Aus) beat A Hansen (Den) 1 hole
R Fisher (Eng) beat R Moore (US) 1 hole
Noh Seung-Yul (S Kor) beat Y.E. Yang (S Kor) 2&1
J Vegas (Ven) beat L Oosthuizen (SA) 1 hole
N Colsaerts (Bel) beat R Goosen (SA) 1 hole
A Quiros (Sp) beat S Kjeldsen (Den) 5&4
J Edfors (Swe) beat MA Jimenez (Sp) 2&1
I Poulter (Eng) halved with P Lawrie (Sco)
Friday afternoon results (top seeds in brackets):
(8) F Molinari (It) bt P Lawrie (Sco) 3&2
(7) C Schwartzel (SA) bt J Edfors (Swe) 5&4
(6) P Casey (Eng) lost to S Kjeldsen (Den) 1hole
(5) Rory McIlroy (NI) lost to N Colsaerts (Bel) 3&2
(4) G McDowell (NI) bt J Vegas (US) 1hole
(3) M Kaymer (Ger) bt Seung-yul Noh (S Kor) 2&1
(2) L Donald (Eng) bt R Fisher (Eng) 3&1
(1) L Westwood (Eng) bt A Baddeley (Aus) 4&3
Seung-yul Noh (Kor) v A Quiros (Sp)
M Kaymer (Ger) v S Kjeldsen (Den)
R Fisher (Eng) v C Schwartzel (SA)
L Donald (Eng) v J Edfors (Swe)
J Vegas (Ven) v N Colsaerts (Bel)
G McDowell (NI) v R McIlroy (NI)
A Baddeley (Aus) v F Molinari (It)
L Westwood (Eng) v I Poulter (Eng)