After a six-under-par 66, Casey lies just a stroke behind leaders Bradley Dredge and Niclas Fasth after the opening day of the Smurfit Kappa European Open at the K Club near Dublin.

It was a performance seen by a massive 29,000 crowd taking advantage of a bank’s free ticket offer and it pushes the 28-year-old, chasing a second successive victory, even closer to securing a second Ryder Cup cap for September’s match on the adjoining Palmer course.

More immediately, it gives Casey the opportunity to take full advantage of Howell’s decision to miss the €3.5m tournament and lead the money list for the first time in his career.

While some might shun away from talking about bad memories when things are going so well, Casey was happy to answer questions about the nightmare slump that lasted the whole of last summer.

The “darkest depths” – as he calls them – came during the BMW Championship at Wentworth when, playing with Ernie Els and Thomas Bjorn, his run of missed cuts went on with back-to-back 78s.

“I didn’t know where the golf ball was going and, yeah, I did occasionally fear for the crowd,” he recalled.

“It became very difficult to see how I could get round the course. The holes and the fairways looked smaller and I was worried about what was going to happen. Now it’s excitement.”

Casey has not finished outside the top 20 in any tournament in Europe or America since the end of February and finally got the win his play deserved at the Johnnie Walker Championship in Scotland two weeks ago.

“The game’s not become easy, but it’s maybe become clearer as to how to get round. I’m going out with a nice anticipation, not worrying.

“I’ve just got a really good attitude in everything. I’ve just got a smile back on my face.

“Whether it’s a good round or a poor round, I’m very happy doing what I’m doing. I’m very lucky to be doing what I’m doing.

“Touch wood, nothing like last year ever happens again, but I think I learned a tremendous amount from it and if a loss of form came around somewhere through the remainder of my career then I think I could hopefully deal with it quicker.”

Casey’s return to form began with the first Ryder Cup qualifying event last September – and he sees this as no coincidence.

“I think it was almost for me as if the slate was wiped clean,” he said. “Everybody was starting afresh.

"It gave me something to chase and a fresh outlook on things.”

Leaders Fasth and Dredge also have Ryder Cup aspirations but, while Casey is currently fifth in the standings, they are 17th and 23rd respectively.

Fasth won the Spanish Open in April and, after being disappointed with his play since, he charged into contention by chipping in for eagle at the long seventh, his 16th, and closed with an 18-foot birdie putt.

Dredge, who with Stephen Dodd won the World Cup for Wales last November, celebrated his 33rd birthday by also going round in a seven-under 65, five of his birdies coming in the last seven holes.

Several of the favourites are still well in touch, world number four Retief Goosen’s 69 being matched by Colin Montgomerie and Darren Clarke, despite their having to contend with windier conditions and rain later in the day.

Defending champion Kenneth Ferrie finished with a double bogey seven for a 73 while, in contrast, Clarke birdied three of the last four and afterwards the crowd as “fantastic. It’s much better to play in front of 29,000 than 2,000.”

American Ryder Cup captain Tom Lehman, partnering Montgomerie and scoring 71 himself, said the fans were “amazing”.

Local favourite Padraig Harrington, second the last two weeks, came in with a 70, but Paul McGinley’s recent struggles continued with a 75. He is down to eighth in the Ryder Cup table and captain Ian Woosnam, paired with him, was unable to spark him into his best form.

Woosnam had the same score and Miguel Angel Jimenez, the third member of the group, a 77 that included a nine on the 600-yard seventh.

After his round, Clarke received his European tour “Shot of the Month” trophy and then announced he was going to auction it and give the proceeds to a breast cancer charity. His wife Heather is battling the illness.

IRISH SCORES: Clarke, McDowell, McGrane -3. Harrington -2. Browne, Hoey, Murphy +1. Higgins, Lawrie, Mortimer, Walton +2. Hamill, McGinley +3, McGovern, Thornton +4.