Ten-man Chelsea shrugged off a red card for captain Conor Gallagher to edge Brighton 3-2 while West Ham drew 1-1 with Crystal Palace.
Chelsea recorded just their second Premier League home win of the season against Brighton, despite being reduced to 10 men before half-time.
Mauricio Pochettino’s men were cruising midway through the first half after goals from Enzo Fernandez and Levi Colwill.
Facundo Buonanotte halved the deficit for the visitors shortly before half-time and there was still time for Gallagher to pick up a second yellow card, changing the complexion of the match.
Fernandez restored Chelsea’s two-goal cushion from the penalty spot, but Joao Pedro struck in stoppage time to heap the pressure on the home side.
Brighton were awarded a penalty for a handball by Colwill in the 101st minute but the referee reversed his on-field decision after reviewing the incident on the pitchside monitor and Chelsea held on.
“Crazy — it’s the most competitive league,” said Pochettino.
“The team is tired, we are all tired but overall happy,” he added. “After Newcastle (a 4-1 defeat), we needed to show a different face. That’s why I’m happy.”
Aston Villa striker Watkins headed home a cross from Moussa Diaby in the 90th minute to rescue a point Unai Emery’s team, which kept them in fourth place.
Earlier, Leon Bailey had cancelled out an opener from Bournemouth’s Antoine Semenyo before Dominic Solanke put the home side back ahead.
“It shows our resilience, but we are not starting games well away from home,” said Watkins.
“If we can iron that out it will help us. Every game we want to win, we are in good form. We fancy ourselves against anybody.”
At the London Stadium, Mohammed Kudus put West Ham ahead in the first half, before Odsonne Edouard equalised in the second period to earn a point for Crystal Palace.