Dwain Chambers saw off the challenge of Britain's promising young sprinters to win his fifth successive 100m title at the British Championships.
Victory in a season's best of 10.12 seconds guaranteed Chambers a place in the British team for August's European Championships in Zurich.
The 36-year-old admitted he would have considered retiring if he had missed out on an eighth domestic crown.
"I thought 'this is it - if you don't make it, you're done'," said Chambers.
The Londoner held off a strong field including Harry Aikines-Aryeetey, Chijindu Ujah and Richard Kilty - regarded as the exciting future of British sprinting.
Chambers's training partner Ujah was expected to continue his recent rise and replicate the headline-grabbing form that saw him run 9.96 seconds this month, becoming only the fifth Briton to go under 10 seconds.
But the 20-year-old fell away as Chambers powered through in the second half of the race.
Ujah crossed the line third in 10.18 seconds, with Aikines-Aryeetey, 25, second in 10.14.
"I knew I was going to have to run for my life," added Chambers, whose best time of the year coming into the championships was 10.24 seconds, set in Beijing in May.
"I train with Chijindu and I know what he's like on the latter part - and I also know he's run faster than me. So in my mind I was like 'just stay ahead of him'. Fortunately it worked out."
With the British Championships doubling as trials for the European Championships, the top two in each event were assured of a place in Zurich, as long as they had also secured the qualifying standard.
But with 10 sprinters, including Chambers, having already dipped under the 10.20-second mark set by British Athletics, Chambers knew he needed a top-two place to guarantee selection.
"I would have had to seriously review my situation," Chambers told BBC Radio 5 live, reflecting on the possibility of not making the team.
"Failure here would have made it very difficult for me to have any more opportunities to compete. I would have probably drawn a line under the season and prepared for next year."
The result leaves Britain's selectors with the difficult decision of having to choose between James Dasaolu - the second fastest Briton in history - and Ujah for the third 100m spot on the team to go to Switzerland.
Dasaolu, who was scheduled to make his comeback at this weekend's trials, had been given special dispensation to miss the event after struggling with injury for most of the year.
The 26-year-old will attempt to convince the selectors at the Diamond League in Lausanne next Thursday and the Glasgow Grand Prix in a fortnight.
There was also a close finish in the women's event, Asha Philip successfully defending her 100m title in a wind-assisted 11.11 seconds.
A photo-finish separated her nearest challengers - Ashleigh Nelson taking second spot ahead of British 200m champion Jodie Williams, with both clocking 11.15 seconds.
Katarina Johnson-Thompson's impressive season continued as the 21-year-old heptathlete set a personal best 6.81m on her way to the long jump title.
Elsewhere, Goldie Sayers, making an incredible comeback after a two-year injury absence, sealed her 11th British javelin title with a 62.75m effort.
The 27-year-old negotiated windy conditions to secure her first British title in 55.58 seconds.
In the 800m, Lynsey Sharp perfectly timed her race to clinch the title, seeing off the challenge of Alison Leonard and Jenny Meadows, with teenager Jessica Judd a disappointing fourth.
Martyn Rooney was another to add to his collection of British titles, the 27-year-old taking the 400m crown for the fifth time in 45.78, having already achieved the qualifying standard. Second-placed Conrad Williams (45.88) has until 13 July to meet the 45.70 mark.
And there was a maiden triumph for Kelly Massey (52.42), the 29-year-old holding off Shana Cox to become British 400m champion.
Jamaican-born Julian Reid was victorious in the triple jump final with a season's best of 16.82m, while British record holder Sophie Hitchon was too good for the rest of the women's hammer field, throwing 65.56m to win by more than two metres.
The men's 5,000m walk saw a British record for Tom Bosworth, who took the title in 19 minutes 29.87 seconds, while Dan Greaves broke the F44 British discus record with a 59.90m throw.