Slovakian goalkeeper Martin Dubravka had kept Newcastle in the game with a string of saves and got a hand to Alonso’s angled left-foot drive but could not keep it out.
A 74th-minute strike from Spanish wing back Marcos Alonso earned Chelsea a deserved 1-0 win over a dogged Newcastle United in the Premier League on Saturday.
Slovakian goalkeeper Martin Dubravka had kept Newcastle in the game with a string of saves and got a hand to Alonso's angled left-foot drive but could not keep it out.
Frank Lampard's young side enjoyed 71% possession and earned 11 corners while conceding none, but until Alonso's goal could not make their superiority tell against a resurgent Newcastle, who defended in numbers and looked dangerous on the counter.
Lampard said he urged his players to show more bravery, intent and momentum in the second half.
"It's there you saw the spirit and urgency in the team," Lampard said. "We had a bit of a problem in the game and we solved it with the way they played in the second half."
Mason Mount, Christian Pulisic, Tammy Abraham and Willian all tested Dubravka from close range.
Lampard praised Pulisic's contribution after he came on in the second half.
The US international has found it hard to find a place in the team since he joined for an American record $73 million this season.
"He's a hot topic because of the price tag," Lampard said. "But we are looking in the long term and there's a lot more to come. He's only 21."
Newcastle's Miguel Almiron and Allan Saint-Maximin troubled Chelsea with pacy moves in the first half, but the side, who beat Manchester United in their last game to move out of the relegation zone, lacked finishing quality.
It was the fifth win in a row in all competitions for Chelsea and the result lifted them into fourth place in the table for the first time this season.
"We know we want to be challenging in the top four and from the slightly difficult start we had it shows we are moving in the right direction, Lampard said. "Being in the top four must only give us the hunger to move on."
Steve Bruce's Newcastle are hovering above the bottom three.
"We looked a threat on the break ...but in the second half we tired a bit and that showed," Bruce said, adding his players needed to make better decisions in the final third.
"The big thing is we've got to find the goals."