Antonio Conte said his team selection at Wembley had been justified after Chelsea beat Southampton 4-2 at Stamford Bridge.
Cesc Fabregas, Diego Costa and Eden Hazard were substitutes in last Saturday’s FA Cup semi-final win over Spurs, largely because of the proximity of this fixture.
And all three were instrumental as Antonio Conte’s side moved within 12 points of the title with five games remaining.
Hazard scored Chelsea’s first following a Fabregas through-ball and Costa lay-off.
Gary Cahill, back after gastroenteritis, headed in Chelsea’s second to give the hosts a half-time lead after ex-Blues midfielder Oriel Romeu netted for Saints.
And Costa notched his 50th Premier League goal from a Fabregas pass to end a seven-match scoreless run early in the second half and added a late fourth before Ryan Bertrand’s late consolation.
Chelsea boss Antonio Conte told Sky Sports: “It was a good win. Today I have to be pleased with the effort of my players. It wasn’t easy after a tough game against Tottenham. Southampton have good players and play good football.
“My choice was right for the game against Tottenham and the game today. It’s not easy to make these strong choices.
“To score at the end of the first half was very important. I was confident. I was seeing the team show a great will to win. In this part of the season, it’s not easy.
“We must be confident for the future. It’s important to look at ourselves and not the other [Spurs].”
Gary Cahill admitted Tuesday’s win was a “massive step” towards the title after Chelsea marched seven points clear of Tottenham.
And Cahill said they can sit back and watch Tottenham sweat at Crystal Palace tomorrow.
“It does feel like a massive step. First time for a long time we’ve played first [before Tottenham in the league],” Cahill told Sky Sports.
“Marcos Alonso popped a nice ball across and it’s great for a defender. It was a great timing [the second goal] and a big boost before half-time. Most important thing is that we get the win.”
On recovering from gastroenteritis, Cahill added: “I feel OK. I’m just recovering.
“The lads didn’t miss me against Tottenham at Wembley. This result leaves us in a good position. We have a big game this weekend [at Everton].”