Rory McIlroy got the improved display he had demanded from himself with a fine six-under-par opening round for a share of the early clubhouse lead at the BMW Championship in St Louis.

After labouring to an eight-over finish at last week’s St Jude Championship, where Scottie Scheffler coasted to victory, the world number two had admitted a positive display again at Bellerive would ‘feel like a win’.

It has been a run of frustrating performances from the back-to-back Masters champion, who had returned to action in Memphis for the first time since he tied for 40th at The Open.

McIlroy, though, showed signs of getting back into his groove as part of the early afternoon wave, with birdies at the fourth and then on eight to turn at two under.

A fine tee shot on the par-three 13th then left the Northern Irishman to roll in a seven-foot putt and he picked up another shot following a lengthy drive on the 492-yard 15th.

McIlroy – sitting 13th in the play-off standings, so assured of making to the 30-man season-ending Tour Championship – continued his momentum to finish with successive birdies and sign for a welcome 64.

The Northern Irishman revealed a bit of “good work” with swing coach Michael Bannon and caddie Harry Diamond after returning home from Memphis had helped him rediscover his touch.

“I felt at least like I got myself back going in the right direction, and what I wanted to do with my swing, but still you never know when you turn up here,” McIlroy said on the Golf Channel.

“This golf course sets up a lot better for me than Memphis did last week. You can miss it a little bit off the tee, and the playing corridors are a lot wider, so you can get away with it, which I needed to get away with it a couple of times today.

“But this set-up suits my game a little bit better, and I definitely feel a little bit more comfortable on this golf course than I did last week.”

American pair Gary Woodland – who slotted in a superb 99-yard eagle on 11 – and Wyndham Clark, having made birdie on five of his last six holes, also both sat at six under.

Japan’s Ryo Hisatsune was at five under, while Englishman Alex Fitzpatrick and Sweden’s Ludvig Aberg were in a group tied for sixth at four under.

Scotland’s Robert MacIntyre also showed an improvement at two under having withdrawn from the St Jude Championship ahead of the second round following his opening 12-over 82.

World number one Scheffler had been in fine form last week with a final round of 66 – but was soon slumped at the other end of the leaderboard after a run of four bogeys through the opening seven holes at Bellerive.

The defending champion recovered a stroke heading into the turn.