Saracens were pushed hard by bottom-of-the-table Newcastle Falcons as the Premiership champions won 37-19.

Saracens got a bonus point thanks to a penalty try after 63 minutes as Callum Chick was sent to the sin-bin.

Mako Vunipola got a fifth try against the 14 men before being sent off.

The Saracens skipper - who was back on after a head injury to replacement Tom West - was red carded after a hit with his shoulder on Bryan Byrne's head in the final play of the match.

Saracens remain in fifth place in the Premiership after Sale Sharks earned a losing bonus point at Northampton Saints.

The home side, who made seven changes for the visit of the winless Falcons, made a mistake from the kick-off, allowing Rory Jennings to convert a first-minute penalty.

Theo Dan went over from close range after 11 minutes with Saracens encamped in the Newcastle red zone having won four penalties as they dominated the possession.

But they were behind thanks to a spectacular 16th-minute Radwan try as the Falcons scrum-half kicked away a Saracens pass that went to ground deep in his own half, kicked again at 40 metres, and collected to race in under the posts.

Falcons thought they had scored a similar try 11 minutes later when Iwan Stephens raced through, but replays showed a knock-on in the build-up and a couple of minutes later the quick-thinking Ivan van Zyl went in from close range with a tap penalty as the hosts regained the lead.

But Jennings kicked two more penalties for Newcastle while Olly Hartley had an excellent try disallowed following a knock-on by van Zyl, but Gonzalez capitalised from a few metres out as Saracens' excellent passing broke through the Falcons who had defended well.

Jennings and Manu Vunipola exchanged penalties early in the second period, but again Newcastle did well to absorb waves of Saracens pressure as the hosts hunted a bonus point try.

Mark McCall's side eventually got a fourth score thanks to a powerful maul that Chick brought down on the Newcastle line, resulting in a yellow card for the Falcons skipper - and against 14 men Saracens got a fifth try when Vunipola went in from a few inches after a close-range line-out.

Vunipola could face a ban after his late red card, which could rule him out of upcoming games against the likes of Leicester Tigers, Bordeaux, Lyon and Exeter Chiefs.

Saracens director of rugby Mark McCall:

[On Mako Vunipola's red card] "He was part of a double-tackle. He came in second, the primary tackler affected the body height of the ball carrier, so we'll see what the [tribunal] panel have to say in a couple of days' time.

"In terms of the performance, into a very strong wind I think we had 90 per cent of possession and territory in the first half and probably did a lot of good things to achieve that.

"Probably our attacking side in the opposition 22 wasn't exactly what we would have liked. At the same time, credit to Newcastle.

"To show the fight and the toughness and the resilience that they did and to defend their line was superb, I thought, given what has happened to them this season.

"We were dominating possession and we were dominating territory, we just had to be a bit better down their end."

Newcastle Falcons head coach Alex Codling told BBC Radio Newcastle:

"Today was really a reflection of the group, how together they are, how hard they're prepared to work for each other.

"The frustration I have, really, is that first half we defended like Trojans, took our opportunity with Adam [Radwan] but just that error before half-time.

"We should have gone in ahead at half-time, but in the end just one error and, to be fair to Saracens, they're very ruthless and they went in ahead of us at the half-time whistle, which was a frustration for us.

"In the second half, at 25-19 behind on 63 minutes, we're certainly in the game, but we just gave too many penalties away at key times and let them in.

"But it's an amazing group to work with, their spirit, their resilience, their courage. We defended to a man like Trojans."

Saracens: Goode; Segun, Daly, Hartley, Cinti; Manu Vunipola, van Zyl; Mako Vunipola (capt), Dan, Judge, McFarland, Tizard , Gonzalez , Knight, Christie.

Replacements: George, West, Hoskins, Isiekwe, Earl, B Vunipola, Simpson, Parton.

Sent off: Mako Vunipola (80).

Newcastle: Penny; Radwan, Moroni, Orlando, Stephens; Jennings, O'Sullivan; Brantingham, Blamire, Bello, McDonald, de Chaves, Rubiolo, Pepper, Chick (capt).

Replacements: B Byrne, Brocklebank, McCallum, Cardall, Leatherbarrow, Elliott, Connon, Wacokecoke.

Sin-bin: Chick (63).

Referee: Jack Makepeace