Lowry, the 2019 Open champion, was chasing his first title since September 2022 – but the 36-year-old was unable to maintain his bid despite finishing each of the first three days at the top of the leaderboard.
He made back-to-back birdies on the 15th and 16th holes to tie par and finish the weekend at nine under in third place.
Scheffler, the 2022 champion by one shot, made six birdies – including four on the back nine – to seal a dominant victory with his best score over the four days.
This is his seventh PGA Tour title, almost a year to the day since he lost victory at the 2023 Players Championship.
Clark, who started the day one shot behind the leaders, carded a two-under 70 to finish second.
Behind Lowry, Americans Russell Henley and Will Zalatoris both finished at seven under, tied for fourth place.
2018 Northern Ireland winner Rory McIlroy, last year’s runner-up, shot 76 on Sunday to finish one under par and tied for 21st.
