Watkins' 16th Premier League goal of the season arrived in first-half stoppage time, as he met Morgan Rogers' low cross with a deft touch. Following a brief VAR check for offside, the goal stood - his 75th for the club in the competition, moving him past Gabriel Agbonlahor as Villa's all-time top scorer in the Premier League era.
"I've had eyes on breaking that record since I joined the club," said the England international. "It's a great achievement, and you need to celebrate wins like that."
Unai Emery's side, now sixth on 63 points, capitalised on Manchester City's earlier draw at Southampton and pulled level with fourth-placed Newcastle and fifth-placed Chelsea, both of whom meet on Sunday. Villa, however, have played one game more than all three of their direct rivals.
Despite largely controlling the match, Villa endured a nervy final 10 minutes after Jacob Ramsey was sent off for a second bookable offence. Bournemouth, quiet for much of the afternoon, pushed forward in search of an equaliser but were denied by a combination of sharp goalkeeping and desperate defending.
Antoine Semenyo fired wide late on, and Villa goalkeeper Emiliano Martínez produced a crucial save to deny Evanilson. Matty Cash then cleared Semenyo's effort off the line deep into added time to preserve the three points.
Earlier, Marco Asensio had struck the post in the 43rd minute before Kepa Arrizabalaga was called into action with a double save to keep out headers from Boubacar Kamara and Cash. Watkins' goal came just moments later - reward for Villa's persistence and control in the first half.
Villa are now guaranteed at least a top-seven finish and a place in Europe next season, regardless of how the final fixtures unfold.
"We're in Europe - Conference League, Europa League or Champions League," said Emery post-match. "To do that three seasons in a row is something I'm very proud of. But we want the biggest prize possible, and we'll keep pushing."
Bournemouth, who stunned Arsenal last weekend, remain in 10th and saw their own faint European hopes take a hit. A finish in eighth could still be enough for a Europa Conference League spot, should Manchester City win the FA Cup, but that route now looks increasingly unlikely.
"There's still a chance, so we'll keep fighting," said manager Andoni Iraola. "We reacted well late on, but it wasn't enough."
With just two games remaining, Villa remain firmly in contention for a top-five finish-and, potentially, a return to the Champions League.
Mikel Arteta has acknowledged that Arsenal entered the 2024–25 campaign knowing their squad lacked depth and included several players prone to injury - limitations that ultimately contributed to another trophyless season.
Man City manager Pep Guardiola has described the 2024/25 campaign as the toughest of his 16-year managerial career, acknowledging a drop in standards and a failure to meet expectations.
Manchester City's bid to cement a top-five finish and secure Champions League football suffered a frustrating setback as they were held to a 0-0 draw by a defiant Southampton side at St Mary's.
Arsenal manager Mikel Arteta has conceded that his side have gone backwards in the Premier League this season, despite progress in European competition.
