Rory McIlroy is heading for his third straight defeat at the Turkish Airlines World Golf Final - but even that would be worth 300,000 US dollars (£187,000).
McIlroy had lost both of his opening matches - to Matt Kuchar and Charl Schwartzel - and needed to beat Tiger Woods on Thursday morning and hope other scores and results went his way to have a chance of reaching the semi-finals.
But the world number one quickly found himself five shots behind Woods and possibly heading for a longed-for afternoon on the beach with girlfriend Caroline Wozniacki.
McIlroy hit his opening drive into a water hazard to the right of the fairway and was forced to take a penalty drop, leading to a bogey five, while he then missed birdie chances at the second and third.
Another bogey came at the par-three sixth before a sole birdie on the front nine at the seventh took the 23-year-old to the turn in 36, one over par.
Woods had also lost his opening match to Schwartzel but shot 67 to beat Kuchar by five on Wednesday and was four under at the turn as he closed in on a place in the last four.
Westwood carded five birdies and an eagle on the fifth - where he hit his drive on the 373-yard par four to within 10 feet - but was only two ahead as Mahan carded five birdies and one bogey.
The eight-man event has a prize fund of 5.2million US dollars, with 1.5million to the winner and 300,000 for seventh and eighth.